ARM: mach-shmobile: fix memory size for kota2_defconfig

The CONFIG_MEMORY_SIZE value is interpreted as a 32 bit integer, which
makes sense on a system without PAE. It appears that a trailing 0 was
appended to the value and after some testing it appears that 0x1e000000 is
the correct value.

Without this patch, building kota2_defconfig results in:

/home/arnd/linux-arm/arch/arm/kernel/setup.c:790:2: warning: large integer implicitly truncated to unsigned type [-Woverflow]

Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>