perf tools: Remove dependency on libnewt

Now that the map browser shares the input routine with the hists
browser, there is no need for using any libnewt routine, so remove all
traces except for honouring NO_NEWT=1 on the makefile command line as an
indication that TUI support is not needed, in fact it just sets
NO_SLANG=1.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-wae5o7xca9m52bj1re28jc5j@git.kernel.org


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