drm/amd/amdgpu: Increase HWIP_MAX_INSTANCE to 10

Seems like newer cards can have even more instances now.
Found by UBSAN: array-index-out-of-bounds in
drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c:318:29
index 8 is out of range for type 'uint32_t *[8]'

Bug: drm/amd#1697


Cc: stable@vger.kernel.org
Signed-off-by: Ernst Sjöstrand <ernstp@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>