media: imx-jpeg: Add support for descriptor allocation from SRAM

media: imx-jpeg: Add support for descriptor allocation from SRAM

Add support for optional allocation of bitstream descriptors from SRAM
instead of DRAM. In case the encoder/decoder DT node contains 'sram'
property which points to 'mmio-sram', the driver will attempt to use
the SRAM instead of DRAM for descriptor allocation, which might improve
performance.

This also helps on i.MX95 rev.A with sporadic SLOTn_STATUS IMG_RD_ERR
bit 11 being triggered during JPEG encoding, which is caused by a bug
fixed on later SoC revisions. The bug occurs less often when using the
SRAM for descriptor storage, but is not entirely mitigated. The following
pipeline triggers the bug when descriptors get allocated from DRAM, the
pipeline often hangs after a few seconds and the encoder driver indicates
"timeout, cancel it":

gst-launch-1.0 videotestsrc ! \
               video/x-raw,width=256,height=256,format=YUY2 ! \
               queue ! v4l2jpegenc ! queue ! fakesink

Tested-by: Ming Qian <ming.qian@oss.nxp.com>
Signed-off-by: Marek Vasut <marek.vasut@mailbox.org>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>