Convert CONFIG_SPL_NAND_LOAD et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_NAND_LOAD
   CONFIG_SYS_NAND_BLOCK_SIZE
   CONFIG_SYS_NAND_PAGE_SIZE
   CONFIG_SYS_NAND_OOBSIZE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/smartweb_defconfig b/configs/smartweb_defconfig
index 3869635..187a001 100644
--- a/configs/smartweb_defconfig
+++ b/configs/smartweb_defconfig
@@ -63,6 +63,9 @@
 CONFIG_MTD_RAW_NAND=y
 # CONFIG_SYS_NAND_USE_FLASH_BBT is not set
 CONFIG_NAND_ATMEL=y
+CONFIG_SYS_NAND_BLOCK_SIZE=0x20000
+CONFIG_SYS_NAND_PAGE_SIZE=0x800
+CONFIG_SYS_NAND_OOBSIZE=0x40
 CONFIG_PHYLIB=y
 CONFIG_ATMEL_USART=y
 CONFIG_USB=y