OMAP4: Tablet2: configure TC35876x panel refresh rate to 60 fps

Current configuration refreshes the LCD at ~70 fps, which is more
than UI expects and also can impact power consumption. This is now corercted to 60 fps.

Change-Id: I98ce97b35f0458b1e24040fe0556aa698b3b00a2
Signed-off-by: Sergiy Kibrik <sergiy.kibrik@globallogic.com>

Conflicts:
	arch/arm/mach-omap2/board-44xx-tablet-panel.c