UPSTREAM: drm: bridge: dw-hdmi: Define and use macros for PHY register addresses

UPSTREAM: drm: bridge: dw-hdmi: Define and use macros for PHY register addresses

Replace the hardcoded register address numerical values with macros to
clarify the code.

This change has been tested by comparing the assembly code before and
after the change.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170117082910.27023-18-laurent.pinchart+renesas@ideasonboard.com
Change-Id: I131045008e021218f1338592999ba4de33fc0883
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
(cherry pick from f0e7f2f3b6333a02dd7cb89822e6330631c9a3e3)