anv: Drop fast-clear value conversion check
What does this MR do and why?
These are reviewed commits from !31374 (merged).
Allow fast clears even if the clear color's interpretation between the image format and view format would result in a different pixel. Since !31743 (merged), we store a clear color for each format used with an image. So, the clear color to use with the image format is always known.
Closes: #5622 (closed)