[commit] [OG10] amdgcn: Add gfx908 support

[Kwok Cheung Yeung]

Hello

I have backported commit 3535402e20118655b2ad4085a6e1d4f1b9c46e92 (amdgcn: Add 
gfx908 support) from mainline to the devel/omp/gcc-10 branch as commit 
bb55967ccde0b48f285150caf6443a327159b4a2. This adds support for the gfx908 GPU type.

Kwok