tools: Copy uapi/asm/perf_regs.h from the kernel

To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.

And check if the copy drifts from the kernel.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-sxf7rpow2blsno5f7t6n0sqz@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>