clk: renesas: rzv2h: Simplify rzv2h_cpg_assert()/rzv2h_cpg_deassert()

clk: renesas: rzv2h: Simplify rzv2h_cpg_assert()/rzv2h_cpg_deassert()

rzv2h_cpg_assert() and rzv2h_cpg_deassert() functions are similar. Share
this code via __rzv2h_cpg_assert(). This avoid code duplication.

Reported-by: Pavel Machek <pavel@denx.de>
Closes: https://lore.kernel.org/cip-dev/Z9QA9rwuXCuVbOXp@duo.ucw.cz/
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20250317083213.371614-4-tommaso.merciai.xr@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>