clk: renesas: r8a77995: Correct parent clock of INTC-AP

According to the R-Car Gen3 Hardware Manual Errata for Rev 0.55 of
September 8, 2017, the parent clock of the INTC-AP module clock on R-Car
D3 is S1D2.

This change has no functional impact.

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