perf: Refactor some common macros to cairo-perf.h

These macros are standard in src's cairoint.h and test's cairo-test.h
internal header files, so for consistency do the same thing with perf's
cairo-perf.h.

Reviewed-by: Uli Schlachter <psychon@znc.in>
NEWS: Add bug links and reword feature and bug descriptions
perf: Refactor some macros to cairo-perf.h

This commit covers one of the left out modifications from
"commit cd11a4ff0421fd293279b202be800550890574bb" by Bryce.
It removes the duplicate macro definition in cairo-perf-diff-files.c
which by default includes the cairo-perf.h having MAX macro defnition.

Signed-off-by: Ravi Nanjundappa <nravi.n@samsung.com>