samples: mei: Fix building on musl libc

samples: mei: Fix building on musl libc

The header bits/wordsize.h is glibc specific and on building on musl
with allyesconfig results in

samples/mei/mei-amt-version.c:77:10: fatal error: bits/wordsize.h: No such file or directory
   77 | #include <bits/wordsize.h>
      |          ^~~~~~~~~~~~~~~~~

mei-amt-version.c build file without bits/wordsize.h on musl and glibc.

However on musl we get the follwing error without sys/time.h

samples/mei/mei-amt-version.c: In function 'mei_recv_msg':
samples/mei/mei-amt-version.c:159:24: error: storage size of 'tv' isn't known
  159 |         struct timeval tv;
      |                        ^~
samples/mei/mei-amt-version.c:160:9: error: unknown type name 'fd_set'
  160 |         fd_set set;
      |         ^~~~~~
samples/mei/mei-amt-version.c:168:9: error: implicit declaration of function 'FD_ZERO' [-Wimplicit-function-declaration]
  168 |         FD_ZERO(&set);
      |         ^~~~~~~
samples/mei/mei-amt-version.c:169:9: error: implicit declaration of function 'FD_SET'; did you mean 'L_SET'? [-Wimplicit-function-declaration]
  169 |         FD_SET(me->fd, &set);
      |         ^~~~~~
      |         L_SET
samples/mei/mei-amt-version.c:170:14: error: implicit declaration of function 'select' [-Wimplicit-function-declaration]
  170 |         rc = select(me->fd + 1, &set, NULL, NULL, &tv);
      |              ^~~~~~
samples/mei/mei-amt-version.c:171:23: error: implicit declaration of function 'FD_ISSET' [-Wimplicit-function-declaration]
  171 |         if (rc > 0 && FD_ISSET(me->fd, &set)) {
      |                       ^~~~~~~~
samples/mei/mei-amt-version.c:159:24: warning: unused variable 'tv' [-Wunused-variable]
  159 |         struct timeval tv;
      |                        ^~

Hence the the file has been included.

Fixes: c52827cc4ddf ("staging/mei: add mei user space example")
Signed-off-by: Brahmajit Das <listout@listout.xyz>
Link: https://lore.kernel.org/r/20250702135955.24955-1-listout@listout.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>