clk: renesas: rcar-gen3: Remove outdated SD_SKIP_FIRST

We handle it differently meanwhile.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20211110191610.5664-7-wsa+renesas@sang-engineering.com


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