cpufreq: pxa: select CPU_FREQ_TABLE

CPUFreq driver of this platform uses APIs from freq_table.c and so must select
CPU_FREQ_TABLE.

Cc: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>