drm/amdgpu: Fix the memory allocation issue in amdgpu_discovery_get_nps_info()

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: Fix the memory allocation issue in amdgpu_discovery_get_nps_info()

Fix two issues with memory allocation in amdgpu_discovery_get_nps_info()
for mem_ranges:

- Add a check for allocation failure to avoid dereferencing a null
pointer.

- As suggested by Christophe, use kvcalloc() for memory allocation,
which checks for multiplication overflow.

Additionally, assign the output parameters nps_type and range_cnt after
the kvcalloc() call to prevent modifying the output parameters in case
of an error return.