cross-build: Include sys/types.h from sys/param.h

FreeBSD has a style(9) enforced assumption that sys/param.h includes
sys/types.h. However, Linux under musl doesn't do this so go ahead and
explicitly include it here. It won't hurt on the glibc systems, and
helps musl.

Co-authored-by:		Val Packett <val@packett.cool>
Sponsored by:		Netflix
Pull Request:		https://github.com/freebsd/freebsd-src/pull/1066
Reviewed by:		val_packett.cool
Differential Revision:	https://reviews.freebsd.org/D45352

tools/build/cross-build/include/linux/sys/param.h

@@ -45,3 +45,5 @@
  * let's use 32 since that will work across all systems
  */
 #define MAXLOGNAME 33 /* max login name length (incl. NUL) */
+
+#include <sys/types.h>