[S390] support XZ compressed kernel

Add support for XZ compressed kernel. Same as on x86 and sh.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/boot/compressed/misc.c b/arch/s390/boot/compressed/misc.c
index 2751b3a..028f23e 100644
--- a/arch/s390/boot/compressed/misc.c
+++ b/arch/s390/boot/compressed/misc.c
@@ -19,6 +19,7 @@
 #undef memset
 #undef memcpy
 #undef memmove
+#define memmove memmove
 #define memzero(s, n) memset((s), 0, (n))
 
 /* Symbols defined by linker scripts */
@@ -54,6 +55,10 @@
 #include "../../../../lib/decompress_unlzo.c"
 #endif
 
+#ifdef CONFIG_KERNEL_XZ
+#include "../../../../lib/decompress_unxz.c"
+#endif
+
 extern _sclp_print_early(const char *);
 
 int puts(const char *s)