Convert CONFIG_ENABLE_36BIT_PHYS to Kconfig

This converts the following to Kconfig:
   CONFIG_ENABLE_36BIT_PHYS

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/P1010RDB-PA_36BIT_SPIFLASH_defconfig b/configs/P1010RDB-PA_36BIT_SPIFLASH_defconfig
index fd2156a..ad30bbb 100644
--- a/configs/P1010RDB-PA_36BIT_SPIFLASH_defconfig
+++ b/configs/P1010RDB-PA_36BIT_SPIFLASH_defconfig
@@ -15,6 +15,7 @@
 CONFIG_SPL_SPI=y
 CONFIG_MPC85xx=y
 CONFIG_TARGET_P1010RDB_PA=y
+CONFIG_ENABLE_36BIT_PHYS=y
 CONFIG_SYS_MPC85XX_NO_RESETVEC=y
 CONFIG_SPL_SYS_MPC85XX_NO_RESETVEC=y
 CONFIG_PHYS_64BIT=y