net: ethernet: renesas: rcar_gen4_ptp: Remove bool conversion

Remove the unnecessary bool conversion and simplify the code.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://patch.msgid.link/20250223233613.100518-2-thorsten.blum@linux.dev


Signed-off-by: Jakub Kicinski <kuba@kernel.org>