Include sys/time.h and pthread.h in tmon.h, so that types
"pthread_mutex_t" and "struct timeval tv" are known when tmon.h
references them.

Without these headers, compiling tmon against musl-libc will fail with
these errors:

In file included from sysfs.c:31:0:
tmon.h:47:8: error: unknown type name 'pthread_mutex_t'
 extern pthread_mutex_t input_lock;
        ^~~~~~~~~~~~~~~
make[3]: *** [<builtin>: sysfs.o] Error 1
make[3]: *** Waiting for unfinished jobs....
In file included from tui.c:31:0:
tmon.h:54:17: error: field 'tv' has incomplete type
  struct timeval tv;
                 ^~
make[3]: *** [<builtin>: tui.o] Error 1
make[2]: *** [Makefile:83: tmon] Error 2
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Acked-by: Alejandro González <alejandro.gonzalez.correo@gmail.com>
Tested-by: Alejandro González <alejandro.gonzalez.correo@gmail.com>
Fixes: 94f69966 ("tools/thermal: Introduce tmon, a tool for thermal  subsystem")
Link: https://lore.kernel.org/r/20220718031040.44714-1-f.fainelli@gmail.comSigned-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>