MIPS: Netlogic: use preset loops per jiffy

MIPS: Netlogic: use preset loops per jiffy

Doing calibrate delay on a hardware thread will be inaccurate since
it depends on the load on other threads in the core. It will also
slow down the boot process when done for 128 hardware threads. Switch
to a pre-computed loops per jiffy based on the core frequency. The
value is computed based on the core frequency and roughly matches the
value calculated by calibrate_delay().

Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4791/
Signed-off-by: John Crispin <blogic@openwrt.org>