ARM: picoxcell: don't reserve irq_descs

All irq_desc's are now dynamically allocated so we don't need to
statically reserve them.

v2:	- select SPARSE_IRQ and set .nr_irqs to NR_IRQS_LEGACY to skip
	ISA and IRQ 0.
Signed-off-by: NJamie Iles <jamie@jamieiles.com>

arch/arm/Kconfig

@@ -650,6 +650,7 @@ config ARCH_PICOXCELL
 	select HAVE_SCHED_CLOCK
 	select HAVE_TCM
 	select NO_IOPORT
+	select SPARSE_IRQ
 	select USE_OF
 	help
 	  This enables support for systems based on the Picochip picoXcell

arch/arm/mach-picoxcell/common.c

@@ -45,7 +45,7 @@ static void __init picoxcell_init_irq(void)
 
 DT_MACHINE_START(PICOXCELL, "Picochip picoXcell")
 	.map_io		= picoxcell_map_io,
-	.nr_irqs	= ARCH_NR_IRQS,
+	.nr_irqs	= NR_IRQS_LEGACY,
 	.init_irq	= picoxcell_init_irq,
 	.handle_irq	= vic_handle_irq,
 	.timer		= &picoxcell_timer,

arch/arm/mach-picoxcell/include/mach/irqs.h

 /*
  * Copyright (c) 2011 Picochip Ltd., Jamie Iles
  *
- * This file contains the hardware definitions of the picoXcell SoC devices.
- *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -16,10 +14,7 @@
 #ifndef __MACH_IRQS_H
 #define __MACH_IRQS_H
 
-#define ARCH_NR_IRQS			64
-#define NR_IRQS				(128 + ARCH_NR_IRQS)
-
-#define IRQ_VIC0_BASE			0
-#define IRQ_VIC1_BASE			32
+/* We dynamically allocate our irq_desc's. */
+#define NR_IRQS				0
 
 #endif /* __MACH_IRQS_H */