ep93xx: Refactoring of the timer code, including the following changes
* use a free running timer instead of a periodical one
* use unsigned long long for total number of ticks
* hold the timer state in a structure instead of separate variables
* increment the timer counter instead of decrementing it
* remove unused function udelay_masked()
* remove unused function set_timer()
Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
c7ad13a242