arm/configs/openbmc: Add palmetto devices snippet

Taken from openbmc tree (v1.0-85-gdbf496725f59) at:

 meta-openbmc-machines/meta-openpower/meta-ibm/meta-palmetto/recipes-kernel/linux/linux-obmc

Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/configs/openbmc_defconfig

@@ -66,6 +66,7 @@ CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_COUNT=4
 CONFIG_BLK_DEV_RAM_SIZE=8192
 CONFIG_ASPEED_BT_IPMI_HOST=y
+CONFIG_EEPROM_AT24=y
 CONFIG_EEPROM_93CX6=y
 CONFIG_SCSI=y
 CONFIG_BLK_DEV_SD=y
@@ -129,9 +130,11 @@ CONFIG_I2C_CHARDEV=y
 CONFIG_SPI=y
 CONFIG_DEBUG_PINCTRL=y
 CONFIG_GPIO_ASPEED=y
+CONFIG_SENSORS_NCT7904=y
 CONFIG_SENSORS_POWER8_OCC_I2C=y
 CONFIG_PMBUS=y
 CONFIG_SENSORS_ADM1275=y
+CONFIG_SENSORS_TMP421=y
 CONFIG_SSB=y
 CONFIG_FB=y
 CONFIG_FB_MODE_HELPERS=y