igb: Clear IMS bits when committing ICR access

igb: Clear IMS bits when committing ICR access

The datasheet says contradicting statements regarding ICR accesses so it
is not reliable to determine the behavior of ICR accesses. However,
e1000e does clear IMS bits when reading ICR accesses and Linux also
expects ICR accesses will clear IMS bits according to:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/intel/igb/igb_main.c?h=v6.2#n8048

Fixes: 3a977deebe ("Intrdocue igb device emulation")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit f0b1df5c4502b5ec89f83417924935ab201511d0)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>