cdx: controller: Drop unneeded driver.pm NULL assignment

Struct driver in platform_driver is zero-ed so there is no need to
assign its 'pm' member to NULL.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20250502-cdx-clean-v3-5-6aaa5b369fc5@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>