v2: rebased, style cleanups, disable mem decode before resize,
handle gmc_v9 as well, round size up to power of two.
v3: handle gmc_v6 as well, release and reassign all BARs in the driver.
v4: rename new function to amdgpu_device_resize_fb_bar,
reenable mem decoding only if all resources are assigned.
v5: reorder resource release, return -ENODEV instead of BUG_ON().
v6: squash in rebase fix
Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>