Convert CONFIG_SYS_FLASH_CFI_WIDTH to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_FLASH_CFI_WIDTH

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/M5282EVB_defconfig b/configs/M5282EVB_defconfig
index 8f38710..42940e1 100644
--- a/configs/M5282EVB_defconfig
+++ b/configs/M5282EVB_defconfig
@@ -30,6 +30,7 @@
 CONFIG_SYS_RX_ETH_BUFFER=8
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_FLASH_CFI_DRIVER=y
+CONFIG_SYS_FLASH_CFI_WIDTH_16BIT=y
 CONFIG_SYS_FLASH_PROTECTION=y
 CONFIG_SYS_FLASH_CFI=y
 CONFIG_DM_ETH=y