drm/amdkfd: Bump up KFD API version for CRIU

 - Change KFD minor version to 7 for CRIU

Proposed userspace changes:
https://github.com/RadeonOpenCompute/criu



Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>