pinctrl: sh-pfc: r8a7795: Re-add DRIF support

DRIF support for r8a7795 was initially added with commit 2d775831
("pinctrl: sh-pfc: r8a7795: Add DRIF support") and later dropped from
the new pfc-r8a7795.c while re-naming the initial pfc-r8a7795.c to
pfc-r8a7795-es1.c in commit b205914c ("pinctrl: sh-pfc: r8a7795:
Add support for R-Car H3 ES2.0"). As the DRIF doesn't differ, re-add
it here.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>