chrp/nvram.c: add MODULE_LICENSE()

Add MODULE_LICENSE() to the chrp nvram.c driver to fix the build
warning message:

WARNING: modpost: missing MODULE_LICENSE() in arch/powerpc/platforms/chrp/nvram.o
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/chrp/nvram.c

@@ -11,6 +11,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/uaccess.h>
@@ -89,3 +90,5 @@ void __init chrp_nvram_init(void)
 
 	return;
 }
+
+MODULE_LICENSE("GPL v2");