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/am335x_evm_defconfig b/configs/am335x_evm_defconfig
index 7fd90ce..7f986bf 100644
--- a/configs/am335x_evm_defconfig
+++ b/configs/am335x_evm_defconfig
@@ -63,6 +63,9 @@
 CONFIG_MMC_OMAP_HS=y
 CONFIG_MTD=y
 CONFIG_MTD_RAW_NAND=y
+CONFIG_SYS_NAND_BLOCK_SIZE=0x20000
+CONFIG_SYS_NAND_PAGE_SIZE=0x800
+CONFIG_SYS_NAND_OOBSIZE=0x40
 CONFIG_DM_SPI_FLASH=y
 CONFIG_SF_DEFAULT_SPEED=24000000
 CONFIG_SPI_FLASH_WINBOND=y