fw update: common: Update software_config regex patterns

Update regex patterns in software_config.cpp to match
the latest hardware compatible scheme.

Test on Harma:
EM settings:
``` json
{
    "Address": "0x61",
    "Bus": 28,
    "FirmwareInfo": {
        "CompatibleHardware":
            "com.meta.Hardware.Harma.VR.ISL69269_vcore0",
        "VendorIANA": 40981
    },
    "Name": "Harma_MB_vr_cpu0_vcore0",
    "Type": "ISL69269Firmware"
},
{
    "Address": "0x62",
    "Bus": 28,
    "FirmwareInfo": {
        "CompatibleHardware":
            "com.meta.Hardware.Harma.VR.ISL69269_vcore1",
        "VendorIANA": 40981
    },
    "Name": "Harma_MB_vr_cpu0_vcore1",
    "Type": "ISL69269Firmware"
},
{
    "Address": "0x63",
    "Bus": 28,
    "FirmwareInfo": {
        "CompatibleHardware":
            "com.meta.Hardware.Harma.VR.ISL69269_pvdd11",
        "VendorIANA": 40981
    },
    "Name": "Harma_MB_vr_cpu0_pvdd11",
    "Type": "ISL69269Firmware"
}
```
Harma updater log
``` bash
root@bmc:~#
    /usr/libexec/phosphor-code-mgmt/phosphor-i2cvr-software-update
<7> requesting dbus name xyz.openbmc_project.Software.I2CVR
<7> Initialized SoftwareManager
<7> [config] looking for dbus interface ...XDPE1X2XXFirmware
<7> [config] looking for dbus interface ...ISL69269Firmware
<7> Found configuration interface at xyz.openbmc_project.EntityManager,
    /.../board/Harma_MB/Harma_MB_vr_cpu0_pvdd11
<7> [config] Voltage regulator device type:
    ISL69269Firmware on Bus: 28 at Address: 99
<7> Harma_MB_vr_cpu0_pvdd11_3351: created dbus interfaces on path
    /xyz/openbmc_project/software/Harma_MB_vr_cpu0_pvdd11_3351
<7> Harma_MB_vr_cpu0_pvdd11_3351: set version 4294049940
<7> [Software] enabling update of
    /.../Harma_MB_vr_cpu0_pvdd11_3351 (adding the update interface)
<7> Found configuration interface at xyz.openbmc_project.EntityManager,
    /.../board/Harma_MB/Harma_MB_vr_cpu0_vcore0
<7> [config] Voltage regulator device type:
    ISL69269Firmware on Bus: 28 at Address: 97
<7> Harma_MB_vr_cpu0_vcore0_916: created dbus interfaces on path
    /xyz/openbmc_project/software/Harma_MB_vr_cpu0_vcore0_916
<7> Harma_MB_vr_cpu0_vcore0_916: set version 4283812141
<7> [Software] enabling update of
    /.../Harma_MB_vr_cpu0_vcore0_916 (adding the update interface)
<7> Found configuration interface at xyz.openbmc_project.EntityManager,
    /.../board/Harma_MB/Harma_MB_vr_cpu0_vcore1
<7> [config] Voltage regulator device type:
    ISL69269Firmware on Bus: 28 at Address: 98
<7> Harma_MB_vr_cpu0_vcore1_3742: created dbus interfaces on path
    /xyz/openbmc_project/software/Harma_MB_vr_cpu0_vcore1_3742
<7> Harma_MB_vr_cpu0_vcore1_3742: set version 4292870292
<7> [Software] enabling update of
    /.../Harma_MB_vr_cpu0_vcore1_3742 (adding the update interface)
<7> Done with initial configuration
```

Change-Id: I2d3155733d6c65e76f4ea6dd9814e6b51b83c228
Signed-off-by: Daniel Hsu <Daniel-Hsu@quantatw.com>
diff --git a/common/src/software_config.cpp b/common/src/software_config.cpp
index 8fb3162..b476afd 100644
--- a/common/src/software_config.cpp
+++ b/common/src/software_config.cpp
@@ -17,7 +17,7 @@
     objectPath(objPath), configName(name), configType(configType),
     vendorIANA(vendorIANA), compatibleHardware(compatible)
 {
-    std::regex reCompatible("([a-zA-Z0-9])+(\\.([a-zA-Z0-9])+)+");
+    std::regex reCompatible("([a-zA-Z0-9_])+(\\.([a-zA-Z0-9_])+)+");
     std::cmatch m;
 
     if (name.empty())