ARM: SAMSUNG: Move the start address of Samsung SoCs' VA space

This patch moves the start address of Samsung SoCs' VA space so that
can use more vmalloc()/ioremap() space. Of course need to change the
VMALLOC_END for it.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>