Fix a race condition while building the recovery patch (needed for msm8226)

RECOVERY_PATCH_INSTALL has a dependency on RECOVERY_FROM_BOOT_PATCH.
This is correct, because RECOVERY_PATCH_INSTALL uses make_recovery_patch
which needs the imgdiff tool. imgdiff on the other hand is a dependency
of RECOVERY_FROM_BOOT_PATCH. This should ensure that all dependencies
are met.
However, RECOVERY_FROM_BOOT_PATCH is defined after
RECOVERY_PATCH_INSTALL, making the dependency effectively non-existant.
Moving RECOVERY_FROM_BOOT_PATCH before RECOVERY_PATCH_INSTALL fixes a
race-condition where sometimes imgdiff was not build before
RECOVERY_PATCH_INSTALL is called.

Upstream is not affected by this bug, since it does not contain
RECOVERY_PATCH_INSTALL anymore.

The following error can be observed whenever someone hits this race
condition (which is basically always reproducible when building with
-j1):
Installing recovery patch to system partition
Warning: could not find SYSTEM/build.prop in <built-in function zip>
using prebuilt recovery.img from BOOTABLE_IMAGES...
using prebuilt boot.img from BOOTABLE_IMAGES...
Traceback (most recent call last):
  File "./build/tools/releasetools/make_recovery_patch", line 55, in <module>
    main(sys.argv[1:])
  File "./build/tools/releasetools/make_recovery_patch", line 51, in main
    common.MakeRecoveryPatch(input_dir, output_sink, recovery_img, boot_img)
  File "build/tools/releasetools/common.py", line 1461, in MakeRecoveryPatch
    _, _, patch = d.ComputePatch()
  File "build/tools/releasetools/common.py", line 1146, in ComputePatch
    p = Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  File "build/tools/releasetools/common.py", line 100, in Run
    return subprocess.Popen(args, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1335, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory
build/core/Makefile:1047: recipe for target
    'out/target/product/t00n/system/bin/install-recovery.sh' failed

Fixes: 3d1c612e ("Revert "Revert "core: Makefile: Build
install-recovery into the system image""")

Change-Id: I28e8c845ffc830553ca5177cbe22ae72b185b437