src/shared/util.h: include sys/types.h

src/shared/util.h: include sys/types.h

Include sys/types.h to avoid the following build failure on musl raised
since commit fb57ad9b9d107856e5f1c8135da04ffa2f7a11ac:

In file included from src/shared/queue.c:15:
./src/shared/util.h:106:1: error: unknown type name 'ssize_t';
did you mean 'size_t'?
  106 | ssize_t util_getrandom(void *buf, size_t buflen, unsigned int flags);
      | ^~~~~~~
      | size_t

Fixes:
 - http://autobuild.buildroot.org/results/83eaeb3863040645409f5787fdbdde79385c5257
Signed-off-by: Manika Shrivastava <manika.sh@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>