Use external header file for kernel space types

The FreeBSD kernel types are not used in Newlib.  Provide them via an
external header file to decouple Newlib and FreeBSD updates for RTEMS.

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>

newlib/libc/sys/rtems/include/machine/_types.h

@@ -35,11 +35,4 @@ typedef	__int64_t	__rlim_t;	/* resource limit - intentionally */
 					/* signed, because of legacy code */
 					/* that uses -1 for RLIM_INFINITY */
 
-#ifdef _KERNEL
-typedef	int		boolean_t;
-typedef	struct device	*device_t;
-typedef	char		vm_memattr_t;	/* memory attribute codes */
-typedef	struct vm_page	*vm_page_t;
-#endif /* _KERNEL */
-
 #endif /* _MACHINE__TYPES_H */

newlib/libc/sys/rtems/include/machine/types.h

@@ -77,4 +77,9 @@ typedef	__uintptr_t	vm_size_t;
 
 typedef	__uintmax_t	rman_res_t;
 
+#ifdef _KERNEL
+/* Header file provided outside of Newlib */
+#include <machine/_kernel_types.h>
+#endif
+
 #endif /* __BSD_VISIBLE */