build: Fix kernel.mk typos

Change-Id: I5980d6a30dd66741a561a95e0dfba60a3ad0ef5d
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
Add new version to qcom_utils.mk

Change-Id: I1ca1532fd4968450715ecd0cca7729e0e6d507ef
Allow a device to generically define its own headers

We have a few cases of devices including specific versions of projects
just because of modified headers (msm_mdp.h comes to mind), and I just
had enough of ifdeffing header files for specific cases (the P990 needs
a lot of these).
Now... if a target defines a TARGET_SPECIFIC_HEADER_PATH, any headers in
there will take precedence over the standard ones; for example, on the
p990, I have

TARGET_SPECIFIC_HEADER_PATH := device/lge/p990/include

which makes, for example, the
device/lge/p990/include/hardware_legacy/AudioHardwareInterface.h be
used instead of
hardware/libhardware_legacy/include/hardware_legacy/AudioHardwareInterface.h
whenever a source file uses <hardware_legacy/AudioHardwareInterface.h>

Change-Id: I41b62668b60e3f62a6ebd3738d8d2675103a81e6