ARM: OMAP: Fix dsp clocks in clock framework

OMAP DSP control registers DSP_CKCTL, DSP_IDLECT1, etc
are not in the IO area, so omap_readw() and omap_writew()
cannot be used with these registers.

Instead __raw_readw() and __raw_writew() must be used.
The DSP virt addr = phys addr.

This fixes audio problems in the recent kernels as pointed
out by Nishant Menon.