build: Add Qualcomm's helper macros

 * This is used everywhere in Qualcomm's code. There's no reason we need
   to constantly replace it with uglier stuff in our Makefiles.

Change-Id: I0183a338470ec96a38f356a47bae65a0d3fb2c95
build: Add board platforms to qcom_utils

Change-Id: I85458167bf2b9c04b029d09b87bf791ff4cfd04d
build: Use common name for QCOM 7K boards.

This is needed to build QCOM HAL without external modifications. The
device would now have to specify msm7x27 or msm7x30 instead of
specifying the full name.

Patch Set 2: Add msm7x27a into the list.

Change-Id: I25018e397b5aad27fab5244731a574ae86752e17