[MIPS] Alchemy: Add au1500 reserved interrupt

In the conversion done in the commits

  95c4eb3ef4484ca85da5c98780d358cffd546b90
  9d360ab4

  [MIPS] Alchemy: Renumber interrupts so irq_cpu can work.

one reserved interrupt on au1500 was missed. this broke the au1000 ethernet
driver.
Signed-off-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

include/asm-mips/mach-au1x00/au1000.h

@@ -615,6 +615,7 @@ enum soc_au1500_ints {
 	AU1000_RTC_MATCH1_INT,
 	AU1000_RTC_MATCH2_INT,
 	AU1500_PCI_ERR_INT,
+	AU1500_RESERVED_INT,
 	AU1000_USB_DEV_REQ_INT,
 	AU1000_USB_DEV_SUS_INT,
 	AU1000_USB_HOST_INT,