radv: check driver name before calling amdgpu.
radv: check driver name before calling amdgpu.

This checks the kernel driver name is amdgpu before calling
libdrm_amdgpu.

This avoids the following error:
amdgpu_device_initialize: DRM version is 1.6.0 but this driver is only compatible with 3.x.x

when run on a machine with i915 graphics as well as amdgpu.

Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler