[CPUFREQ] CPU_FREQ_TABLE shouldn't be a def_tristate

CPU_FREQ_TABLE enables helper code and gets select'ed when it's required.

Building it as a module when it's not required doesn't seem to make much sense.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>