OMAPDSS: HDMI: Add OMAP5 HDMI support

This adds a new driver to omapdss for OMAP5 HDMI. However, the new
driver uses common HDMI files which are shared with OMAP4 HDMI driver.

OMAP5 HDMI has a different HDMI core IP compared to OMAP4, but has very
similar PLL and PHY IPs which can be handled with common code.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>