igt_fb: Transfer existing content to Cairo surface for Y/Yf frame buffers
igt_fb: Transfer existing content to Cairo surface for Y/Yf frame buffers

Rendering into Y and Yf tiled frame buffers with Cairo was losing the
previous content ie. was starting from black. This is different than the
behaviour with linear and X tiled so make it the same by blitting the
initial content when creating the rendering context.

Signed-off-by: Tvrtko Ursulin <82325a91373a06cdf12f953d4611ffb7756aa8d4@intel.com>
Cc: Damien Lespiau <64bd3cb94f359c1a3ce68dae5e26b40578526277@intel.com>
Signed-off-by: Damien Lespiau <64bd3cb94f359c1a3ce68dae5e26b40578526277@intel.com>

tiagovignatti/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools,dlespiau/checkmate-test-igt,dlespiau/checkmate-test-igt,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools