[POWERPC] ps3: always make sure were running on a PS3

Add missing checks to PS3 specific drivers ps3av and sys-manager to verify that
we are actually running on a PS3 (pointed out by Arnd).

Correct existing checks in other subsystems/drivers to return -ENODEV instead
of zero.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
diff --git a/drivers/ps3/sys-manager.c b/drivers/ps3/sys-manager.c
index 0fc30be..3aa2b0d 100644
--- a/drivers/ps3/sys-manager.c
+++ b/drivers/ps3/sys-manager.c
@@ -22,7 +22,10 @@
 #include <linux/module.h>
 #include <linux/workqueue.h>
 #include <linux/reboot.h>
+
+#include <asm/firmware.h>
 #include <asm/ps3.h>
+
 #include "vuart.h"
 
 MODULE_AUTHOR("Sony Corporation");
@@ -598,6 +601,9 @@
 
 static int __init ps3_sys_manager_init(void)
 {
+	if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
+		return -ENODEV;
+
 	return ps3_vuart_port_driver_register(&ps3_sys_manager);
 }