[ARM] 4405/1: NSLU2, DSM-G600 frequency fixup code

This patch is required as the frequency fixup in nslu2_init does not
run sufficiently early in the boot sequence to take effect. In addition
the dsmg600 setup code behaviour has been improved such that a
'fixup' routine is avoided.

Signed-off-by: Michael-Luke Jones <mlj28@cam.ac.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>