pwm: ftm: Correctly track usage count
pwm: ftm: Correctly track usage count

No matter how many times the FTM PWM is enabled, the use_count will
always be one.

Signed-off-by: Xiubo Li <cf2f21a5d63bafab3dac1a48e01d31cd0b77ab89@freescale.com>
Signed-off-by: Thierry Reding <b75a4d02013b0e68ae2c6bb0dcfd4b7bec282dc9@gmail.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs