Old platforms using ancient gettimeoffset() and other arcane
APIs are standing in the way of cleaning up the ARM kernel.
The gettimeoffset() was also broken: it would try to read out
the timer counter value, while this would not work (the
counter statically returns the initially programmed value)
so the implementation would anyway fall back to a homebrew
version of jiffie calculation.

This is an attempt at blind-coding a generic time and clocksource
driver for the platform by way of a datasheet and looking at the
old code.

Tested-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>