media: hantro: Avoid global variable for jpeg quantization tables

On a system with multiple encoders present, it's possible for two
encoders to write to the global luma and chroma quantization tables at
the same time if they both submit a JPEG frame to be encoded. Avoid
this race by moving the tables into the `jpeg_ctx` structure which is
stored on the stack.

Signed-off-by: James Cowgill <james.cowgill@blaize.com>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>