Register 0x1910 unmasks interrupts and legacy INTx interrupts are unmasked
because driver does not support individual masking yet.

Link: https://lore.kernel.org/r/20220222155030.988-11-pali@kernel.orgSigned-off-by: NPali Rohár <pali@kernel.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>