This extends the pwm_dw sample app to build for
FRDM_K64F board also. Because of this, pwm_dw
has been renamed to pwm.
This allows us to put it through sanity test
to catch build breakage.
Change-Id: Ie4d7442af43ede58f4cec0ec28643384a685321a
Signed-off-by: Daniel Leung <daniel.leung@intel.com>