msm8960-common: remove redundant qcom cflag

QCOM_HARDWARE flag is already set when BOARD_USES_QCOM_HARDWARE is
defined. See build/core/qcom_target.mk.

Change-Id: Idb684629d229d6b9cd3d6a932a49d303367162b3
msm8960-common: Select QCOM power HAL

Change-Id: I39adbae1b78e4a2462dc12bbd54198d3212f8cf6