benchtests: Rename argument to TIMING_INIT macro.

benchtests: Rename argument to TIMING_INIT macro.

The TIMING_INIT macro currently sets the number of loop iterations
to 1000, which limits usefulness. Make the argument a clock
resolution value and multiply by 1000 in bench-skeleton.c instead
to allow easier reuse.

ChangeLog:

2013-09-11  Will Newton  <will.newton@linaro.org>

	* benchtests/bench-timing.h (TIMING_INIT): Rename ITERS
	parameter to RES. Remove hardcoded 1000 value.
	* benchtests/bench-skeleton.c (main): Pass RES parameter
	to TIMING_INIT and multiply result by 1000.