pwm_ab and pwm_cd are already inherited from meson.dtsi, we only need to
define the correct "compatible" string so the pwm-meson driver can
choose the parent clocks correctly.
pwm_ef is added to meson8.dtsi directly (similar to how it's done in
meson8b.dtsi) as this controller only exists on Meson8 and Meson8b.
Signed-off-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>