Enabling sample_c optimization for Broadwell GPUs

[André Almeida]

Hi there,

While browsing an old downstream kernel, I found a patch[0] that enables 
sample_c optimizations at Broadwell GPUs. The message from the upstream 
commit that enables it for Haswell[1] (and presumably where the code 
at[0] was copied from) states that "[..] later platforms remove this 
bit, and apparently always enable the optimization".

Could you confirm that Broadwell and following architectures enable this 
optimization by default (and thus, patch[0] is a no-op), or should I 
upstream it?

Thanks,
	André

[0] 
https://github.com/ValveSoftware/steamos_kernel/commit/198990f13e1d9429864c177d9441a6559771c5e2

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=944115934436b1ff6cf773a9e9123858ea9ef3da