uio: uio_pdrv_genirq: Remove dummy PM handling

uio: uio_pdrv_genirq: Remove dummy PM handling

Since commit 63d00be69348fda4 ("PM: runtime: Allow unassigned
->runtime_suspend|resume callbacks"), unassigned
.runtime_{suspend,resume}() callbacks are treated the same as dummy
callbacks that just return zero.

As the Runtime PM callbacks were the only driver-specific PM handling,
all PM handling can be removed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/a5495b6068dd4e40ae7e0fb66b067fd5b5c210b2.1756999260.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>