TF-A: Fix non-standard frequency issue in udelay
TF-A: Fix non-standard frequency issue in udelay

Previous implementation of timers assumed that clk_div has pretty
representation in MHz (10MHz, 100MHz, etc). Unusual frequencies
(99.99MHz) were causing assertion error and made udelay unusable.

Signed-off-by: Max Shvetsov <554ef60c0309fcb96f307a2e251c72d0c11c8b0b@arm.com>
Change-Id: Ic915fff224369d113fd9f8edbcfff169fca8beac

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware