ppc: qemu: Enable RTC support via I2C

The QEMU ppce500 target integrates a Freescale I2C controller and
has a Pericom pt7c4338 RTC connected to it. Enable corresponding
DM drivers so that 'date' command is actually useful.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/configs/qemu-ppce500_defconfig b/configs/qemu-ppce500_defconfig
index 8798db6..536fe7d 100644
--- a/configs/qemu-ppce500_defconfig
+++ b/configs/qemu-ppce500_defconfig
@@ -31,11 +31,14 @@
 CONFIG_BLK=y
 CONFIG_HAVE_BLOCK_DEVICE=y
 CONFIG_MPC8XXX_GPIO=y
+CONFIG_DM_I2C=y
+CONFIG_SYS_I2C_FSL=y
 # CONFIG_MMC is not set
 CONFIG_DM_ETH=y
 CONFIG_E1000=y
 CONFIG_DM_PCI=y
 CONFIG_PCI_MPC85XX=y
+CONFIG_DM_RTC=y
 CONFIG_DM_SERIAL=y
 CONFIG_SYS_NS16550=y
 CONFIG_SYSRESET=y