Convert CONFIG_SYS_MONITOR_BASE to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_MONITOR_BASE

Note that for how this is re-used on some PowePC platforms, we introduce
CONFIG_SPL_SYS_MONITOR_BASE and CONFIG_TPL_SYS_MONITOR_BASE and use the
CONFIG_VAL macro to get the correct value at build time, in the code.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/armadillo-800eva_defconfig b/configs/armadillo-800eva_defconfig
index 4f00b20..d0e457f 100644
--- a/configs/armadillo-800eva_defconfig
+++ b/configs/armadillo-800eva_defconfig
@@ -13,6 +13,7 @@
 CONFIG_TARGET_ARMADILLO_800EVA=y
 CONFIG_SYS_CLK_FREQ=50000000
 CONFIG_SYS_LOAD_ADDR=0x44000000
+CONFIG_SYS_MONITOR_BASE=0x00000000
 CONFIG_BOOTDELAY=3
 # CONFIG_CMDLINE_EDITING is not set
 # CONFIG_AUTO_COMPLETE is not set