power: qpnp-smb2: Update the SMB2 charger driver

Update the QPNP SMB2 charger driver for the
msm-3.18 kernel. The following are the updates -

1. Support the legacy SPMI driver design
2. Remove USB psy (implemented in the USB software stack)
3. Add present and charger-type power supply notifications

CRs-Fixed: 2076000
Change-Id: Ic75231efd460579754a46ca8745880b037f5daf3
Signed-off-by: Ankit Sharma <ansharma@codeaurora.org>
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>