OMAP2 clock: dynamically allocate CPUFreq frequency table

Dynamically allocate the CPUFreq frequency table on OMAP2xxx chips.
This fixes some compilation problems, since the kernel may not know
what chip it is running on until boot-time.  This also reduces the size
of the CPUFreq frequency table.

Problem originally reported by Felipe Balbi <felipe.balbi@nokia.com>.
Thanks also for comments on the patch from Felipe and Kevin.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>