libdrm,intel: rework android header handling

Contains the following patches squashed in:

    commit 99247a5bd724ddcf0f06a5518baad207c53f1e2b
    Author: Haitao Huang <haitao.huang@intel.com>
    Date: Fri, 27 Apr 2012 13:20:53 -0500

        Android.mk: use LOCAL_COPY_HEADERS to export headers.

        Export necessary header files used by other components for
        Android, such as libva intel-driver, gralloc, hwcomposer, etc.

        Change-Id: I2feabf6941379ef4d756e942f30eba059de641f1
Signed-off-by: Haitao Huang <haitao.huang@intel.com>
        [chad: Fixed inconsistent indentation.]
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

    commit 7d0b528cb69995d7ea4e29b2daa1e3b28a362f42
    Author: Emil Velikov <emil.l.velikov@gmail.com>
    Date: Sun, 27 Jul 2014 18:22:41 +0100

        android: reuse headers lists, separate libdrm from intel headers

        Rather than having a duplicate copy of the headers list(s),
        reuse the existing one(s). Distinguish that the intel headers
        should be copied when libdrm_intel is used.

        v2 Rename the headers variable(s) to *_H_FILES.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

    commit 361de3ba4cadd5357596d1537bb3f216d281532b
    Author: Piotr Luc <piotr.luc@intel.com>
    Date: Fri, 14 Jun 2013 13:00:39 +0200

        Export include dir from libdrm

        BZ: 116218

        Google introduced new method of specifying include path(s)
        between modules. This allows a module to include header from a
        library without directly specifyining by includer the path where
        headers are located.

        The method requires from library that holds headers to export
        include path(s) in LOCAL_EXPORT_C_INCLUDE_DIRS variable.
        These exported include path(s) are automatically added to
        include path(s) of modules that have name of the library in the
        LOCAL_SHARED_LIBRARIES or LOCAL_STATIC_LIBRARIES list.

        This change sets LOCAL_EXPORT_C_INCLUDE_DIRS to folders that
        contain headers file that used by other modules in order to
        export these paths.

        Change-Id: Id1ac885b31ef2efe194e0289fbcaecd9eb533df0
Signed-off-by: Piotr Luc <piotr.luc@intel.com>
        Reviewed-on: http://android.intel.com:8080/113562


Reviewed-by: cactus <cactus@intel.com>
Reviewed-by: Luc, Piotr <Piotr.Luc@intel.com>
Reviewed-by: Purushothaman, Vijay A <vijay.a.purushothaman@intel.com>
Reviewed-by: Stimson, Dale B <dale.b.stimson@intel.com>
Tested-by: Stimson, Dale B <dale.b.stimson@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

    commit 2bf22fcbd4cbb9e7c7764d5eff0bb4e75ab1a005
    Author: Emil Velikov <emil.l.velikov@gmail.com>
    Date: 27 Jul 2014 18:27:21 +0100

        android: Separate libdrm and intel LOCAL_EXPORT_C_INCLUDE_DIRS

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>