[ARM] arm32: Fix hard-coded weight in arch_delay_loop_cycles()

With recent implementation, the hard-coded weight used for converting delay loop count to delay loop machine cycles has changed (Don't know why ??).

I have tested thoroughly on BeagleBoard-xM & Hackberry to find the new weight. The new weight seems to be 3 and not 2.

Signed-off-by: Anup Patel <anup@brainfault.org>