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/ls2088ardb_qspi_defconfig b/configs/ls2088ardb_qspi_defconfig
index f702a39..5014eb4 100644
--- a/configs/ls2088ardb_qspi_defconfig
+++ b/configs/ls2088ardb_qspi_defconfig
@@ -33,6 +33,7 @@
 CONFIG_BOOTCOMMAND="sf probe 0:0; sf read 0x806c0000 0x6c0000 0x40000; env exists mcinitcmd && env exists secureboot && esbc_validate 0x806C0000; sf read 0x80d00000 0xd00000 0x100000; env exists mcinitcmd && fsl_mc lazyapply dpl 0x80d00000; run distro_bootcmd;run qspi_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_GREPENV=y