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/seaboard_defconfig b/configs/seaboard_defconfig
index 68a1045..fb67ce6 100644
--- a/configs/seaboard_defconfig
+++ b/configs/seaboard_defconfig
@@ -12,6 +12,8 @@
 CONFIG_SYS_LOAD_ADDR=0x1000000
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_USE_PREBOOT=y
+CONFIG_SPL_FOOTPRINT_LIMIT=y
+CONFIG_SPL_MAX_FOOTPRINT=0x8000
 CONFIG_SYS_PROMPT="Tegra20 (SeaBoard) # "
 CONFIG_SYS_MAXARGS=64
 CONFIG_SYS_PBSIZE=2086