anv/copy: Fix copying Images from Buffers with larger dimensions

anv/copy: Fix copying Images from Buffers with larger dimensions

This function previously assumed that the Buffer and Image had matching
dimensions. However, it is possible to copy from a Buffer with larger
dimensions than the Image. Modify the copy function to enable this.

v2: Use ternary instead of MAX for setting bufferExtent (Jason Ekstrand)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95292
Signed-off-by: Nanley Chery <nanley.g.chery@intel.com>
Tested-by: Matthew Waters <matthew@centricular.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>