clk: renesas: r8a779g0: cpg_pll_configs should be __initconst

cpg_pll_configs[] is only used during initialization.  Hence make it
__initconst, so it will be freed later.

Fixes: 0ab55cf1 ("clk: renesas: cpg-mssr: Add support for R-Car V4H")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/ea806a096d47382f4f560b20f1038f03b4e44e0e.1720794214.git.geert+renesas@glider.be