ppc4xx: Clean up 440 exceptions handling

- Introduced dedicated switches for building 440 and 405 images required
  for 440-specific machine instructions like 'rfmci' etc.

- Exception vectors moved to the proper location (_start moved away from
  the critical exception handler space, which it occupied)

- CriticalInput now serviced (with default handler)

- MachineCheck properly serviced (added a dedicated handler and return
  subroutine)

- Overall cleanup of exceptions declared with STD_EXCEPTION macro (unused,
  unhandled and those not relevant for 4xx were eliminated)

- Eliminated Linux leftovers, removed dead code

Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>
Signed-off-by: Rafal Jaworowski <raj@semihalf.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/include/ppc440.h b/include/ppc440.h
index 07f75de..4bb644e 100644
--- a/include/ppc440.h
+++ b/include/ppc440.h
@@ -82,10 +82,7 @@
 #define	 ivor13 0x19d	/* interrupt vector offset register 13 */
 #define	 ivor14 0x19e	/* interrupt vector offset register 14 */
 #define	 ivor15 0x19f	/* interrupt vector offset register 15 */
-#if defined(CONFIG_440GX) || \
-    defined(CONFIG_440EP) || defined(CONFIG_440GR) || \
-    defined(CONFIG_440EPX) || defined(CONFIG_440GRX) || \
-    defined(CONFIG_440SP) || defined(CONFIG_440SPE)
+#if defined(CONFIG_440)
 #define	 mcsrr0 0x23a	/* machine check save/restore register 0 */
 #define	 mcsrr1 0x23b	/* mahcine check save/restore register 1 */
 #define	 mcsr	0x23c	/* machine check status register */