ARM: shmobile: rcar-gen2: Stop passing mode pins state to clock driver

Now the R-Car Gen2 CPG clock driver obtains the state of the mode pins
from the R-Car RST driver, there's no longer a need to pass this state
explicitly. Hence we can just call of_clk_init() instead.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>