drm/amdgpu: add module parameter choose runtime method

Default runtime logic not changed.
Provide an alternative runtime method. (set 1 to use BACO; 2 to use BAMACO)
When set reset_method to 4, it will use BACO or BAMACO for gpu reset,
according to runpm value.

Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>