power: qpnp-smbcharger: improve HVDCP detection

The current driver calls HVDCP detection work for any type of USB charger.
It should be called only if the initial detection was DCP. While at it
add few log statements to help with debugging.

Change-Id: Iaef4b8e6b4109a6a5033b75823f3f9590ee5ea2c
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>