pinctrl: sh-pfc: r8a77995: Remove USB0_IDIN and USB0_IDPU pins

R-Car Gen3 Hardware Manual Errata for Rev 0.55 of September 8, 2017
removed the USB0_IDIN and USB0_IDPU pins on R-Car D3.

This change has no functional impact, as these definitions were unused.

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