[POWERPC] Editable kernel command-line in zImage binary.

zImage will set /chosen/bootargs (if it is otherwise empty) with the
contents of a buffer in the section "__builtin_cmdline".  This permits
tools to edit zImage binaries to set the command-line eventually
processed by vmlinux.

--
Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/prom.h b/arch/powerpc/boot/prom.h
index 3e2ddd4..a57b184 100644
--- a/arch/powerpc/boot/prom.h
+++ b/arch/powerpc/boot/prom.h
@@ -31,4 +31,11 @@
 	return call_prom("getprop", 4, 1, phandle, name, buf, buflen);
 }
 
+
+static inline int setprop(void *phandle, const char *name,
+			  void *buf, int buflen)
+{
+	return call_prom("setprop", 4, 1, phandle, name, buf, buflen);
+}
+
 #endif				/* _PPC_BOOT_PROM_H_ */