pinctrl: sh-pfc: r8a7791: Remove bogus ctrl marks from qspi_data4_b group

The qspi_data4_b_mux[] array contains pin marks for the clock and chip
select pins.  The qspi_data4_b_pins[] array rightfully does not contain
the corresponding pin numbers, as the control pins are provided by a
separate group (qspi_ctrl_b).

Fixes: 2d0c386f ("pinctrl: sh-pfc: r8a7791: Add QSPI pin groups")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>