Enable hwmon and sensor drivers

hwmon core, nct7904, lm75, and at24.
diff --git a/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc/hwmon.cfg b/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc/hwmon.cfg
new file mode 100644
index 0000000..053fea3
--- /dev/null
+++ b/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc/hwmon.cfg
@@ -0,0 +1,4 @@
+CONFIG_HWMON=y
+CONFIG_SENSORS_NCT7904=y
+CONFIG_SENSORS_LM75=y
+CONFIG_EEPROM_AT24=y
diff --git a/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc_%.bbappend b/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc_%.bbappend
index 6d7ae27..0575ac1 100644
--- a/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc_%.bbappend
+++ b/meta-openbmc-bsp/meta-aspeed/meta-ast2400/recipes-kernel/linux/linux-obmc_%.bbappend
@@ -1,2 +1,2 @@
 FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
-SRC_URI += "file://defconfig"
+SRC_URI += "file://defconfig hwmon.cfg"