power: supply: smb347-charger: Add delay before getting IRQSTAT

This delay-fix is picked up from downstream driver,
we measured that 25 - 35 ms delay ensure that we get required data.

Tested on SMB347 on Nexus 7 2012. Otherwise IRQSTAT_E fails to provide
correct information.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>