power: rename ALLOW_DETECTION to DPF_DMF

The ALLOW_DETECTION property is meant to reflect that the power supply
controller should relinquish USB's DP and DM lines and put them in a
floating state.

Change to use the DP_DM property with DPF_DMF values for floating and
DPR_DMR values for removing the float of DP/DM lines.

Change-Id: I1fdfaceb88058a6d1d3f21205a1a9b0e5058e7e7
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>