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/ls2080ardb_SECURE_BOOT_defconfig b/configs/ls2080ardb_SECURE_BOOT_defconfig
index b799f34..715eb8c 100644
--- a/configs/ls2080ardb_SECURE_BOOT_defconfig
+++ b/configs/ls2080ardb_SECURE_BOOT_defconfig
@@ -30,6 +30,7 @@
 CONFIG_BOOTCOMMAND="env exists mcinitcmd && env exists secureboot && esbc_validate 0x5806C0000; env exists mcinitcmd && fsl_mc lazyapply dpl 0x580d00000;run distro_bootcmd;run nor_bootcmd; env exists secureboot && esbc_halt;"
 CONFIG_MISC_INIT_R=y
 CONFIG_RESET_PHY_R=y
+CONFIG_SPL_MAX_SIZE=0x16000
 CONFIG_SYS_MAXARGS=64
 CONFIG_SYS_PBSIZE=532
 CONFIG_CMD_IMLS=y