As pointed out in the following thread, the CLOCK_TICK_RATE setting for
IXP4xx is incorrect b/c the HW ignores the lowest 2 bits of the LATCH
value.

   http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2005-August/030950.html

Tnx to George Anziger and Egil Hjelmeland for finding the issue.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>