ipq806x: add platform usb support

This change adds DWC3 QCOM USB phys and TCSR drivers. These are
cherry-picked from the following LKML threads:
*dwc3 qcom: https://lkml.org/lkml/2014/9/12/599
*tcsr: https://lkml.org/lkml/2015/2/9/579



We're also adding an additional patch to add the corresponding dev nodes
in the IPQ806x and AP148 dts files.

Signed-off-by: Mathieu Olivari <mathieu@codeaurora.org>

SVN-Revision: 45261