power: regulator: Allow PWM regulator to be omitted from SPL.

This patch allows to enable the PWM regulator driver
independent for U-Boot and SPL.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2 files changed