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/ls2080aqds_qspi_defconfig b/configs/ls2080aqds_qspi_defconfig
index 88ba551..6359a73 100644
--- a/configs/ls2080aqds_qspi_defconfig
+++ b/configs/ls2080aqds_qspi_defconfig
@@ -26,6 +26,7 @@
 CONFIG_BOOTARGS="console=ttyS0,115200 root=/dev/ram0 earlycon=uart8250,mmio,0x21c0500 ramdisk_size=0x2000000 default_hugepagesz=2m hugepagesz=2m hugepages=256"
 CONFIG_BOOTCOMMAND="fsl_mc apply dpl 0x580d00000 && cp.b $kernel_start $kernel_load $kernel_size && bootm $kernel_load"
 CONFIG_RESET_PHY_R=y
+CONFIG_SPL_MAX_SIZE=0x16000
 CONFIG_SYS_MAXARGS=64
 CONFIG_SYS_PBSIZE=532
 CONFIG_CMD_GREPENV=y