Convert CONFIG_SYS_MAX_FLASH_SECT to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_MAX_FLASH_SECT

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/MCR3000_defconfig b/configs/MCR3000_defconfig
index 6adba43..086507e 100644
--- a/configs/MCR3000_defconfig
+++ b/configs/MCR3000_defconfig
@@ -83,6 +83,7 @@
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_FLASH_CFI_DRIVER=y
 CONFIG_SYS_FLASH_CFI=y
+CONFIG_SYS_MAX_FLASH_SECT=35
 CONFIG_MTD_RAW_NAND=y
 CONFIG_MPC8XX_FEC=y
 # CONFIG_PCI is not set