clk: renesas: r9a07g044: Rename CLK_PLL2_DIV16 and CLK_PLL2_DIV20 macros

Rename the macros CLK_PLL2_DIV16->CLK_PLL2_DIV2_8 and
CLK_PLL2_DIV20->CLK_PLL2_DIV2_10 to match the clock tree mentioned in
the hardware manual(Rev.1.00 Sep, 2021).

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211110082019.28554-1-biju.das.jz@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>