venus: add VK_KHR_fragment_shading_rate support

What does this MR do and why?

venus: add VK_KHR_fragment_shading_rate support

Related MRs:

• protocol: virgl/venus-protocol!82 (merged)
• virglrenderer: virgl/virglrenderer!1343 (merged)

Test with anv on ADL-P:

1. dEQP-VK.fragment_shading_rate.*

Test run totals:
  Passed:        2116/106642 (2.0%)
  Failed:        0/106642 (0.0%)
  Not supported: 104526/106642 (98.0%)
  Warnings:      0/106642 (0.0%)
  Waived:        0/106642 (0.0%)

2. dEQP-VK.api.fragment_shading_rate

Test run totals:
  Passed:        3/3 (100.0%)
  Failed:        0/3 (0.0%)
  Not supported: 0/3 (0.0%)
  Warnings:      0/3 (0.0%)
  Waived:        0/3 (0.0%)

3. dEQP-VK.pipeline.fragment_shading_rate

Test run totals:
  Passed:        1881/17902 (10.5%)
  Failed:        0/17902 (0.0%)
  Not supported: 16021/17902 (89.5%)
  Warnings:      0/17902 (0.0%)
  Waived:        0/17902 (0.0%)