gst1-imx: bump to version 0.12.2

Changelog:
* imxv4l2videosrc:
  * Stricter checks for video device capabilities
  * Add support for more video formats like 8/16-bit grayscale

* pxp: Fix incorrect return code which broke blitter with GStreamer 1.8

* blitter:
  * Improvements in error logging
  * Fixes for RGBx framebuffer format detection
  * Fix for subtle tearing problem by implementing triple buffering

* audio:
  * Replace objdump-based scan during build configuration
    Codec filenames are instead moved to the C code; the libdir
    path of the libfslaudiocodec.pc file is used to know where on
    the target the files are placed
  * Explicitely add the libfslaudiocodec.pc libdir to the MP3 encoder
    Fixes build errors in buildroot
  * Minor logging fixes

* misc:
  * Proper check for region copies in phys_mem_meta
  * Add missing G_END_DECLS lines in headers

Tested with the following commands on i.MX6Q (IPU):
 # gst-launch-1.0 playbin uri=file:///root/tears_of_steel_1080p.webm


 # gst-launch-1.0 filesrc location=/root/tears_of_steel_1080p.webm ! \
   matroskademux ! imxvpudec ! imxipuvideosink
 # gst-launch-1.0 filesrc location=/root/tears_of_steel_1080p.webm ! \
   matroskademux ! imxvpudec ! imxeglvivsink

Tested with the following commands on i.MX7 (PXP):
 # gst-launch-1.0 imxv4l2videosrc device=/dev/video1 ! imxpxpvideosink

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>