pinctrl: sh-pfc: r8a7791: Fix scifb2_data_c pin group

The entry for "scifb2_data_c" in the SCIFB2 pin group array contains a
typo, thus the group cannot be selected.

Fixes: 50884519 ("pinctrl: sh-pfc: r8a7791 PFC support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>