msdkjpegdec: add BGRA in src pad

MediaSDK may support RGB4 output for JPEG decoder when the color format
of the input is YUV 4:4:4, so add BGRA in src pad for such input.
Without this fix, the output format is NV12 for YUV 4:4:4 input.
22 jobs for msdk-mjpeg-dec-bgra in 89 minutes and 20 seconds (queued for 16 seconds)
latest
Status Job ID Name Coverage
  Preparation
passed #886461
gst indent

00:00:30

passed #886460
manifest

00:00:41

 
  Build
passed #886471
build cerbero cross-android universal

00:11:56

manual #886475
gst-ios-12.2 allowed to fail manual
build cerbero cross-ios universal
passed #886472
build cerbero cross win32

00:07:43

passed #886473
build cerbero cross win64

00:07:50

passed #886470
build cerbero fedora x86_64

00:06:00

passed #886474
gst-macos-10.14
build cerbero macos x86_64

00:09:14

passed #886466
build clang fedora x86_64

00:06:50

passed #886462
build fedora x86_64

00:05:22

passed #886469
docker windows 1607
build msys2

00:18:02

passed #886463
build nodebug fedora x86_64

00:05:03

passed #886464
build static fedora x86_64

00:12:38

passed #886465
build static nodebug fedora x86_64

00:06:19

passed #886467
docker windows 1607
build vs2017 amd64

00:16:10

passed #886468
docker windows 1607
build vs2017 x86

00:14:56

 
  Test
failed #886476
check fedora

00:03:45

passed #886477
integration testsuites fedora

00:38:55

passed #886478
valgrind bad

00:05:58

 
  Integrate
passed #886479
cross-android universal examples

00:05:04

skipped #886481
gst-ios-12.2 allowed to fail manual
cross-ios universal examples
passed #886480
documentation

00:02:22

 
Name Stage Failure
failed
check fedora Test
           Total: 3157
Uploading artifacts...
gst-build/build/meson-logs/: found 2 matching files
validate-logs: found 3576 matching files

Uploading artifacts to coordinator... ok
id=886476 responseStatus=201 Created token=yTAsKfUL
Uploading artifacts...
validate-logs/*.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=886476 responseStatus=201 Created token=yTAsKfUL
ERROR: Job failed: exit code 1