power: smb5: configure input from wireless

Wireless power feeds to the DCIN input of the smb5 charger and relies
on input current configurations for power draw.

Provide means to configure the current limits via DC psy. Also set the
initial DC ICL to 1A.

Change-Id: Ic4ca30ecac2f4c0dd9080b221b4eaa2e04c4c404
Signed-off-by: Harry Yang <harryy@codeaurora.org>