omapdss: HDMI: create a PHY library

omapdss: HDMI: create a PHY library

HDMI PHY is a block common to DSS in OMAP4, OMAP5 and DRA7x. Move the
existing functions from ti_hdmi_4xxx_ip.c to a separate file. These funcs are
called directly from the hdmi driver rather than hdmi_ip_ops function pointer
calls.

Add the PHY library function declarations to ti_hdmi.h. These will be shared
amongst the omap4/5 hdmi platform drivers. Remove the PHY function pointer ops
from the ti_hdmi_ip_ops struct.

The DT/hwmod information for hdmi doesn't split the address space according to
the required sub blocks. Keep the address offset and size information in the
driver for now. This will be removed when the driver gets the information
correctly from DT/hwmod.

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