ARM: shmobile: Enable HIGHMEM in shmobile_defconfig

Many mach-shmobile hardware platforms include support for more
than 1GiB of RAM. Enable HIGHMEM by default to allow use of
larger amounts of memory.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/configs/shmobile_defconfig

@@ -25,6 +25,7 @@ CONFIG_SCHED_MC=y
 CONFIG_HAVE_ARM_ARCH_TIMER=y
 CONFIG_NR_CPUS=8
 CONFIG_AEABI=y
+CONFIG_HIGHMEM=y
 CONFIG_ZBOOT_ROM_TEXT=0x0
 CONFIG_ZBOOT_ROM_BSS=0x0
 CONFIG_ARM_APPENDED_DTB=y