[PARISC] Rewrite timer_interrupt() and gettimeoffset() using "unsigned" math.
[PARISC] Rewrite timer_interrupt() and gettimeoffset() using "unsigned" math.

It's just a bit easier to follow and timer code is complex enough.

So far, only tested on A500-5x (64-bit SMP), ie: gettimeoffset() code
hasn't been tested at all.

Signed-off-by: Grant Grundler <fd58b8293aeebb072b32124aef6e8da71dd5739c@parisc-linux.org>
Signed-off-by: Kyle McMartin <3c25b01657254677d3e1a8fd1f0742c5d489bd39@parisc-linux.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs