arm64: dts: colibri-imx8x: Add colibri pwm b, c, d

Add Colibri PWM_B, PWM_C, PWM_D to the module-level device-tree and set
the status to ok on the eval-board.

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>