mfd: stmfx: Fix stmfx_irq_init error path

mfd: stmfx: Fix stmfx_irq_init error path

BugLink: https://bugs.launchpad.net/bugs/1885322
[ Upstream commit 60c2c4bcb9202acad4cc26af20b44b6bd7874f7b ]

In case the interrupt signal can't be configured, IRQ domain needs to be
removed.

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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>