powerpc/85xx/defconfig: Remove duplicate CONFIG_RTC_DRV_DS1307

Commit a95e8c28b3dc "powerpc/defconfig: update RTC support" duplicated
the CONFIG_RTC_DRV_DS1307 symbol in mpc85xx_defconfig and
mpc85xx_smp_defconfig, resulting in this:

arch/powerpc/configs/mpc85xx_smp_defconfig:217:warning: override: reassigning to symbol RTC_DRV_DS1307

Fixes: a95e8c28b3dc "powerpc/defconfig: update RTC support"
Cc: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/arch/powerpc/configs/mpc85xx_defconfig b/arch/powerpc/configs/mpc85xx_defconfig
index 8b2d759..d2c4154 100644
--- a/arch/powerpc/configs/mpc85xx_defconfig
+++ b/arch/powerpc/configs/mpc85xx_defconfig
@@ -213,7 +213,6 @@
 CONFIG_RTC_DRV_DS1374=y
 CONFIG_RTC_DRV_DS3232=y
 CONFIG_RTC_DRV_CMOS=y
-CONFIG_RTC_DRV_DS1307=y
 CONFIG_DMADEVICES=y
 CONFIG_FSL_DMA=y
 # CONFIG_NET_DMA is not set
diff --git a/arch/powerpc/configs/mpc85xx_smp_defconfig b/arch/powerpc/configs/mpc85xx_smp_defconfig
index a3003b2..8746008 100644
--- a/arch/powerpc/configs/mpc85xx_smp_defconfig
+++ b/arch/powerpc/configs/mpc85xx_smp_defconfig
@@ -214,7 +214,6 @@
 CONFIG_RTC_DRV_DS1374=y
 CONFIG_RTC_DRV_DS3232=y
 CONFIG_RTC_DRV_CMOS=y
-CONFIG_RTC_DRV_DS1307=y
 CONFIG_DMADEVICES=y
 CONFIG_FSL_DMA=y
 # CONFIG_NET_DMA is not set