qpnp-smb2: Support faking input current limited state

Support faking input current limited state. This is very helpful
in testing/debugging the software based vbus changing algorithms.

Change-Id: I7cf548c94397ee680c9d65343c49ec7b16873e88
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>