pinctrl: sh-pfc: r8a77990: Fix IOCTRL reg state after s2ram on R-Car E3

Due to an interaction with commit 9f2b76a2 ("pinctrl: sh-pfc:
r8a77990: Add R8A774C0 PFC support"), the state of the I/O Control
Registers is saved/restored during s2ram on RZ/G2E, but not on R-Car E3.
Hence on R-Car E3, SDHI voltage state is lost after system resume.

Fix this by registering the I/O Control Registers on R-Car E3, too.

Fixes: 33847a71 ("pinctrl: sh-pfc: r8a77990: Add voltage switch operations for SDHI")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>