pwm: fsl-ftm: Enable support for the new SoC i.MX8QM

Enabled the support for the new SoC i.MX8QM by adding the compatible
string of "fsl,imx8qm-ftm-pwm" and its per-compatible data with setting
"has_enable_bits" to "true".

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>