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/uniphier_ld4_sld8_defconfig b/configs/uniphier_ld4_sld8_defconfig
index c0e4f15..b07f055 100644
--- a/configs/uniphier_ld4_sld8_defconfig
+++ b/configs/uniphier_ld4_sld8_defconfig
@@ -18,6 +18,7 @@
 CONFIG_LOGLEVEL=6
 CONFIG_SPL_MAX_SIZE=0x10000
 CONFIG_SPL_PAD_TO=0x20000
+CONFIG_SPL_BSS_MAX_SIZE=0x2000
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_SPL_NOR_SUPPORT=y
 CONFIG_CMD_CONFIG=y