PEL: Update check for identifying I2C dev paths

Due to changes in the kernel, I2C device paths changed slightly and so
the code that identifies if a device path passed in for a callout is for
an I2C device needs an update.

An example of a new canonical device path is:
```
/sys/devices/platform/ahb/1e780000.apb/1e780000.apb:bus@1e78a000/1e78a200.i2c/i2c-3/3-006d
```

Tested:
Creating a PEL with CALLOUT_DEVICE_PATH=/sys/bus/i2c/devices/3-006d on
an IBM Everest system generates a proper callout, as shown in this
captured PEL debug UserData section:

```
"I2C: bus: 3 address: 109 dest: /sys-0/node-0/bellavista-0/Power-riser-conn-0/Fansipan-0/power-supply-conn-2/power-supply-0/power-supply-blackbox-0"
```

Change-Id: I4efb9135982f417560172df99dfe36f98e3a9696
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/extensions/openpower-pels/device_callouts.cpp b/extensions/openpower-pels/device_callouts.cpp
index fac7cd3..21c3e3c 100644
--- a/extensions/openpower-pels/device_callouts.cpp
+++ b/extensions/openpower-pels/device_callouts.cpp
@@ -506,7 +506,7 @@
         return CalloutType::fsi;
     }
 
-    if (devPath.find("i2c-bus/i2c-") != std::string::npos)
+    if (devPath.find("i2c-") != std::string::npos)
     {
         return CalloutType::i2c;
     }