media: platform: Refactor mtk_jpeg_find_format()

Delete the unused ctx parameter.
Using mtk_jpeg_formats and num_formats parameters is more generic,
because that jpeg enc will also use it.
Delete the macro definition of MTK_JPEG_FMT_TYPE_OUTPUT and
MTK_JPEG_FMT_TYPE_CAPTURE, because that MTK_JPEG_FMT_FLAG_DEC_OUTPUT
and MTK_JPEG_FMT_FLAG_DEC_CAPTURE are enough.

Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Xia Jiang <xia.jiang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>