drm/amdkfd: Remove call to deprecated init_memory interface

This patch removes a call to kfd-->kgd interface function that is doing H/W
initialization. That function is moved into radeon to be part of the common
H/W initialization sequence. The interface function will be deleted.

Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>