Convert CONFIG_SPL_PAD_TO et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_PAD_TO
   CONFIG_SPL_MAX_SIZE
   CONFIG_TPL_PAD_TO
   CONFIG_TPL_MAX_SIZE

Note that we need to make TPL_MAX_SIZE be hex, and so move and convert the
existing places.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/omap3_logic_somlv_defconfig b/configs/omap3_logic_somlv_defconfig
index b497346..4afc37b 100644
--- a/configs/omap3_logic_somlv_defconfig
+++ b/configs/omap3_logic_somlv_defconfig
@@ -21,6 +21,7 @@
 CONFIG_PREBOOT="setenv preboot;saveenv;"
 CONFIG_DEFAULT_FDT_FILE="logicpd-som-lv-37xx-devkit.dtb"
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
+CONFIG_SPL_MAX_SIZE=0xec00
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 # CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is not set
 # CONFIG_SPL_FS_EXT4 is not set