mfd: stmfx: Reset chip on resume as supply was disabled

mfd: stmfx: Reset chip on resume as supply was disabled

[ Upstream commit e583649d87ec090444aa5347af0927cd6e8581ae ]

STMFX supply is disabled during suspend. To avoid a too early access to
the STMFX firmware on resume, reset the chip and wait for its firmware to
be loaded.

Fixes: 06252ade9156 ("mfd: Add ST Multi-Function eXpander (STMFX) core driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>