ARM: ixp4xx_defconfig: add MTD_PHYSMAP

Without MTD_PHYSMAP/MTD_PHYSMAP_OF the flash partitions of my welltech,epbx100
are not detected.

Link: https://lore.kernel.org/r/20210504193457.4008384-3-clabbe@baylibre.com
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/configs/ixp4xx_defconfig

@@ -109,6 +109,8 @@ CONFIG_MTD_REDBOOT_PARTS=y
 CONFIG_MTD_BLOCK=y
 CONFIG_MTD_CFI=y
 CONFIG_MTD_CFI_INTELEXT=y
+CONFIG_MTD_PHYSMAP=y
+CONFIG_MTD_PHYSMAP_OF=y
 CONFIG_MTD_COMPLEX_MAPPINGS=y
 CONFIG_MTD_IXP4XX=y
 CONFIG_MTD_RAW_NAND=m