Fix minor()/major() build failure due to glibc 2.28

glibc 2.28 no longer includes <sys/sysmacros.h> from <sys/types.h>,
and therefore <sys/sysmacros.h> must be included explicitly when
major()/minor() are used.

This commit directly includes <sys/sysmacros.h> into cramfsck.c and
mkcramfs.c files where minor() and major() macros are used.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
---
diff -urpN host-cramfs-1.1.orig/cramfsck.c host-cramfs-1.1/cramfsck.c
--- host-cramfs-1.1.orig/cramfsck.c	2018-09-27 16:48:09.704782201 +0200
+++ host-cramfs-1.1/cramfsck.c	2018-09-27 16:49:12.841138657 +0200
@@ -38,6 +38,7 @@
 
 #define _GNU_SOURCE
 #include <sys/types.h>
+#include <sys/sysmacros.h>
 #include <stdio.h>
 #include <stdarg.h>
 #include <sys/stat.h>
diff -urpN host-cramfs-1.1.orig/mkcramfs.c host-cramfs-1.1/mkcramfs.c
--- host-cramfs-1.1.orig/mkcramfs.c	2018-09-27 16:48:09.712782246 +0200
+++ host-cramfs-1.1/mkcramfs.c	2018-09-27 16:48:59.777064921 +0200
@@ -24,6 +24,7 @@
 
 #define _GNU_SOURCE
 #include <sys/types.h>
+#include <sys/sysmacros.h>
 #include <stdio.h>
 #include <sys/stat.h>
 #include <unistd.h>