omapdss: HDMI: remove hdmi_ip_data struct

The struct hdmi_ip_data contains information related to HDMI wrapper, PLL, PHY
and core sub-blocks. Now that each of these sub blocks has it's own struct,
hdmi_ip_data serves no purpose. The mutex lock in the struct was also never
used.

Remove this struct to make things cleaner.

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