Implement read_edid() for HDMI by implementing necessary functions to
hdmi.c and to hdmi_omap4_panel.c.

Cc: Mythri P K <mythripk@ti.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

regn divider is currently programmed to the registers without change,
but when calculating clock frequencies it is used as regn+1.

To make this similar to how DSI handles the dividers this patch changes
the regn value to be used as such for calculations, but the value
programmed to registers is regn-1.

This simplifies the clock frequency calculations, makes it similar to
DSI, and also allows us to use regn value 0 as undefined.

Cc: Mythri P K <mythripk@ti.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Functions that are included in HDMI IP driver is renamed to have
IP specific names so that it will not conflict with similar functions
from other IP.
Signed-off-by: NMythri P K <mythripk@ti.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Move HDMI IP dependent audio functions from HDMI DSS file  to IP library.
Signed-off-by: NMythri P K <mythripk@ti.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

Split the current HDMI driver to move the HDMI IP dependent ( PLL/PHY/Core
configuration code) to a new IP file (ti_hdmi_4xxx_ip.c.
This is to separate IP dependent OMAP agnostic code from OMAP specific DSS
dependent code.
Signed-off-by: NMythri P K <mythripk@ti.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>