ARM: mach-shmobile: extend clock definitions on sh7372

Add definitions for DV_CLKI and HDMI clocks, extend support for PLLC2 and some
other clocks.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>