ARM: shmobile: lager: correct memory map

The base address of the second memory region on the lager
board is 0x140000000. Update the tag used in the dts file accordingly.

This is a documentation fix and should have no run-time affect.

This problem was introduced when the second memory region
was added to the lager dts file by 62bc32a2


("ARM: shmobile: Include all 4 GiB of memory on Lager)"
in v3.14.

Reported-by: NAOYA SHIIBA <naoya.shiiba.nx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>