Convert CONFIG_SYS_USE_NORFLASH et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_USE_NORFLASH
   CONFIG_SYS_USE_BOOT_NORFLASH

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/at91sam9263ek_norflash_boot_defconfig b/configs/at91sam9263ek_norflash_boot_defconfig
index 0e96b3a..bcd52f6 100644
--- a/configs/at91sam9263ek_norflash_boot_defconfig
+++ b/configs/at91sam9263ek_norflash_boot_defconfig
@@ -6,6 +6,7 @@
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_TARGET_AT91SAM9263EK=y
 CONFIG_ATMEL_LEGACY=y
+CONFIG_SYS_USE_NORFLASH=y
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x10000
 CONFIG_ENV_SECT_SIZE=0x10000
@@ -16,7 +17,6 @@
 CONFIG_DEBUG_UART_CLOCK=100000000
 CONFIG_DEBUG_UART=y
 CONFIG_SYS_LOAD_ADDR=0x22000000
-CONFIG_SYS_EXTRA_OPTIONS="SYS_USE_BOOT_NORFLASH"
 CONFIG_BOOTDELAY=3
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 # CONFIG_DISPLAY_BOARDINFO is not set
diff --git a/configs/at91sam9263ek_norflash_defconfig b/configs/at91sam9263ek_norflash_defconfig
index 20a1050..68c3dcc 100644
--- a/configs/at91sam9263ek_norflash_defconfig
+++ b/configs/at91sam9263ek_norflash_defconfig
@@ -7,6 +7,7 @@
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_TARGET_AT91SAM9263EK=y
 CONFIG_ATMEL_LEGACY=y
+CONFIG_SYS_USE_NORFLASH=y
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x10000
 CONFIG_ENV_SECT_SIZE=0x10000
@@ -17,7 +18,6 @@
 CONFIG_DEBUG_UART_CLOCK=100000000
 CONFIG_DEBUG_UART=y
 CONFIG_SYS_LOAD_ADDR=0x22000000
-CONFIG_SYS_EXTRA_OPTIONS="SYS_USE_NORFLASH"
 CONFIG_BOOTDELAY=3
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 # CONFIG_DISPLAY_BOARDINFO is not set