power: smb1360: Add parallel-charging support

SMB1360 can be configured for charging in a parallel mode.
In this configuration, SMB is the primary charger and it controls
all the charging parameters for the secondary charger. This mode
is only supported with a 10mohm rsense configuration of SMB1360.

SMB1360 enables the secondary charger for charging when it
detects a strong charger. The secondary charging is disabled
when
1. A weak charger is plugged in
2. SMB detects charge termination
3. JEITA soft/hard conditions are hit.

To enable parallel charging the following DT properties must
be defined:

For SMB1360:
qcom,parallel-charging-enabled;
qcom,rsense-10mhom;

For LBC (QPNP Linear charger):
qcom,parallel-charger;

CRs-Fixed: 771178
Change-Id: Ida45524526e43da552cb636dec96b41300cacc17
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>