tests/kms_fbc_crc: extract fill_mmap_{cpu,gtt}()
tests/kms_fbc_crc: extract fill_mmap_{cpu,gtt}()

Just like we have fill_render() and fill_blt(). I'm also going to use
fill_mmap_gtt() for the code that generates the reference CRCs.

Signed-off-by: Paulo Zanoni <cc0e04a2103c45cd195651d976f79813d0f66bdf@intel.com>

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