drm/amdgpu: Replace deprecated function strcpy() with strscpy()

Instead of using the strcpy() deprecated function to populate the
fw_name, use the strscpy() function

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy


Signed-off-by: Andres Urian Florez <andres.emb.sys@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>