BugLink: https://bugs.launchpad.net/bugs/1864773

[ Upstream commit 1ecd8c9c ]

The err_rst_reqb, ext_clki, lowpwr, and ref_clko pin groups are present,
but no pinmux functions refer to them, hence they can not be selected.

Fixes: 1e7d5d84 ("sh-pfc: Add emev2 pinmux support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>