pinctrl: sh-pfc: r8a77990: Fix MOD_SEL0 bit16 when using NFALE and NFRB_N

According to the R-Car Gen3 Hardware Manual Errata for Rev 1.00 of Aug
24, 2018, the MOD_SEL0 bit16 must be set to 0 when the NFALE_A and
NFRB_N_A pin functions are selected.

Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>