pinctrl: sh-pfc: r8a77980: Add QSPI pins, groups, and functions

Add the QSPI{0|1} pins/groups/functions to the R8A77980 PFC driver.

[Sergei: ported to the upstream driver, fixed up the swapped QSPI0 SPCLK/
SSL pins, fixed up the comments, moved the QSPI pins/groups/functions to
be in the alphanumeric order, removed unneeded empty lines, renamed the
patch.]

Signed-off-by: Dmitry Shifrin <dmitry.shifrin@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>