tools include: Grab copies of arm64 dependent unistd.h files

tools include: Grab copies of arm64 dependent unistd.h files

Will be used for generating the syscall id/string translation table.

The arm64 unistd.h file simply #includes the asm-generic/unistd.h, so,
since we will want to know whether either change, we grab both:

  arch/arm64/include/uapi/asm/unistd.h

and

  include/uapi/asm-generic/unistd.h

Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20180706163434.1b64ffbcc0284fb79982f53b@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>