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/sniper_defconfig b/configs/sniper_defconfig
index 483b371..ef2f49f 100644
--- a/configs/sniper_defconfig
+++ b/configs/sniper_defconfig
@@ -11,6 +11,7 @@
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_BOOTCOMMAND="setenv boot_mmc_part ${kernel_mmc_part}; if test reboot-${reboot-mode} = reboot-r; then echo recovery; setenv boot_mmc_part ${recovery_mmc_part}; fi; if test reboot-${reboot-mode} = reboot-b; then echo fastboot; fastboot 0; fi; part start mmc ${boot_mmc_dev} ${boot_mmc_part} boot_mmc_start; part size mmc ${boot_mmc_dev} ${boot_mmc_part} boot_mmc_size; mmc dev ${boot_mmc_dev}; mmc read ${kernel_addr_r} ${boot_mmc_start} ${boot_mmc_size} && bootm ${kernel_addr_r};"
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
+CONFIG_SPL_MAX_SIZE=0xec00
 # CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is not set
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=2