clk: renesas: rzg2l: Use core->name for clock name

clk: renesas: rzg2l: Use core->name for clock name

core->name already contains the clock name thus, there is no
need to check the GET_SHIFT(core->conf) to decide on it.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230912045157.177966-11-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>