Convert CONFIG_MTD_PARTITIONS et al to Kconfig

This converts the following to Kconfig:
   CONFIG_MTD_PARTITIONS
   CONFIG_MTD_DEVICE

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig b/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig
index 1225b40..3c7293b 100644
--- a/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig
+++ b/configs/BSC9131RDB_SPIFLASH_SYSCLK100_defconfig
@@ -25,6 +25,7 @@
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_FSL_CAAM=y
 # CONFIG_MMC is not set
+CONFIG_MTD_PARTITIONS=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_SPANSION=y
 CONFIG_PHY_MARVELL=y