meta-obmc-machines: Add RTC_DRV_RV8803 to Witherspoon and Romulus kernel

Witherspoon and Romulus contain an Epson RX8900CE RTC which is supported
by the RV8803 kernel driver. This patch enables it now that the RTC is
enabled in the respective device trees.

See this commit for Witherspoon:
 6c628de9d450b ARM: dts: witherspoon: add Epson RX8900CE RTC module

And this commit for Romulus:
 c5682cbc3542a arm: dts: Add Romulus BMC machine

Change-Id: I336a6a19c455d2e20084e7fd92c29404ccd5851c
Signed-off-by: Chris Smart <chris@distroguy.com>
diff --git a/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg b/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg
index 45e7a1c..886137e 100644
--- a/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg
+++ b/meta-witherspoon/recipes-kernel/linux/linux-obmc/witherspoon.cfg
@@ -2,3 +2,4 @@
 CONFIG_SENSORS_TMP421=y
 CONFIG_SENSORS_MAX31785=y
 CONFIG_SENSORS_UCD9000=y
+CONFIG_RTC_DRV_RV8803=y