sh: sh7785lcr: fix PCI address map for 32-bit mode

Fix the problem that cannot work PCI device on 32-bit mode because
influence of the commit 68b42d1b548be1840aff7122fdebeb804daf0fa3
("sh: sh7785lcr: Map whole PCI address space."). So this patch was
implement like a 29-bit mode, map whole physical address space of
DDR-SDRAM.

Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>