perf report: Fix build with NO_NEWT=1

Commit ad0de097 "Enable the runtime switching of perf data file" broke
the build with NO_NEWT=1:

    CC builtin-report.o
builtin-report.c: In function '__cmd_report':
builtin-report.c:479:15: error: 'K_SWITCH_INPUT_DATA' undeclared (first use in this function)
builtin-report.c:479:15: note: each undeclared identifier is reported only once for each function it appears in
builtin-report.c: In function 'cmd_report':
builtin-report.c:823:13: error: 'K_SWITCH_INPUT_DATA' undeclared (first use in this function)
make: *** [builtin-report.o] Error 1

Fix it by adding a dummy definition of K_SWITCH_INPUT_DATA.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1361854923-1814-2-git-send-email-michael@ellerman.id.au


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