drm/amdgpu: Use drm_calloc_large for VM page_tables array

It can be big, depending on the VM address space size, which is tunable
via the vm_size module parameter.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93721


Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org