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/bitmain_antminer_s9_defconfig b/configs/bitmain_antminer_s9_defconfig
index f26776d..be5b8a0 100644
--- a/configs/bitmain_antminer_s9_defconfig
+++ b/configs/bitmain_antminer_s9_defconfig
@@ -28,6 +28,7 @@
 # CONFIG_DISPLAY_CPUINFO is not set
 CONFIG_CLOCKS=y
 CONFIG_SPL_MAX_SIZE=0x30000
+CONFIG_SPL_BSS_MAX_SIZE=0x100000
 CONFIG_SPL_STACK_R=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="antminer> "