PXA cpus maximum frequency depends on the cpu (624 for
pxa270, 520 for pxa272, 416 for pxa271). It should be
provided on kernel or module start (cpu-pxa
pxa27x_maxfreq parameter).

Make use of cpufreq_frequency_table_cpuinfo (patch by Bill
Reese provided by Philipp Zabel).

Some additionnal fixes from Philipp Zabel include :
 * rename PXA cpufreq driver to reflect added PXA27x support
 * remove unused variable ramstart from PXA cpufreq driver
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Robert Jarzmik <rjarzmik@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>