Convert CONFIG_SPL_BSS_MAX_SIZE et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_BSS_MAX_SIZE
   CONFIG_SPL_MAX_FOOTPRINT

Note that the da850evm platforms were violating the "only use one" rule
here, and so now hard-code their BSS limit.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/microblaze-generic_defconfig b/configs/microblaze-generic_defconfig
index a919d8b..a7698ac 100644
--- a/configs/microblaze-generic_defconfig
+++ b/configs/microblaze-generic_defconfig
@@ -24,6 +24,8 @@
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_DISPLAY_BOARDINFO=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y
+CONFIG_SPL_FOOTPRINT_LIMIT=y
+CONFIG_SPL_MAX_FOOTPRINT=0xffb00
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_NOR_SUPPORT=y