This patch adds wrappers for MMIO access to ELBI, PHY, and other
registers.  No functional change.

[bhelgaas: changelog]
Signed-off-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NJingoo Han <jg1.han@samsung.com>