tests/amdgpu: add jpeg tests support

v2:
- remove dec create/destroy msg as its not relevant to jpeg (Leo)
- enable the test for jpeg2/jpeg3 (Leo)
- validate checksum of result (Leo)
- add appropriate comments (Leo)

v3:
- linux style function definition indent (James)
- use multiline comment delimiter (Leo)

Signed-off-by: Sathishkumar S <sathishkumar.sundararaju@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>