MIPS: Add architectural FDC IRQ fields

Add architectural field definitions relating to the Fast Debug Channel
(FDC) interrupt, namely the pending bit in Cause and the field in
IntCtl to specify which CPU IRQ line the FDC interrupt is routed to.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9139/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mipsregs.h

@@ -428,6 +428,8 @@
  *
  * Refer to your MIPS R4xx0 manual, chapter 5 for explanation.
  */
+#define INTCTLB_IPFDC		23
+#define INTCTLF_IPFDC		(_ULCAST_(7) << INTCTLB_IPFDC)
 #define INTCTLB_IPPCI		26
 #define INTCTLF_IPPCI		(_ULCAST_(7) << INTCTLB_IPPCI)
 #define INTCTLB_IPTI		29
@@ -458,6 +460,8 @@
 #define	 CAUSEF_IP6		(_ULCAST_(1)   << 14)
 #define	 CAUSEB_IP7		15
 #define	 CAUSEF_IP7		(_ULCAST_(1)   << 15)
+#define	 CAUSEB_FDCI		21
+#define	 CAUSEF_FDCI		(_ULCAST_(1)   << 21)
 #define	 CAUSEB_IV		23
 #define	 CAUSEF_IV		(_ULCAST_(1)   << 23)
 #define	 CAUSEB_PCI		26