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/socrates_defconfig b/configs/socrates_defconfig
index d902019..28ea447 100644
--- a/configs/socrates_defconfig
+++ b/configs/socrates_defconfig
@@ -9,6 +9,7 @@
 CONFIG_MPC85xx=y
 # CONFIG_CMD_ERRATA is not set
 CONFIG_TARGET_SOCRATES=y
+CONFIG_ENABLE_36BIT_PHYS=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y