[MIPS] Make I8259A_IRQ_BASE customizable

Move I8259A_IRQ_BASE from asm/i8259.h to asm/mach-generic/irq.h and
make it really customizable.  And remove I8259_IRQ_BASE declared on
some platforms.  Currently only NEC_CMBVR4133 is using custom
I8259A_IRQ_BASE value.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/i8259.h b/include/asm-mips/i8259.h
index 4df8d8b..e88a016 100644
--- a/include/asm-mips/i8259.h
+++ b/include/asm-mips/i8259.h
@@ -18,6 +18,7 @@
 #include <linux/spinlock.h>
 
 #include <asm/io.h>
+#include <irq.h>
 
 /* i8259A PIC registers */
 #define PIC_MASTER_CMD		0x20
@@ -42,8 +43,6 @@
 
 extern void init_i8259_irqs(void);
 
-#define I8259A_IRQ_BASE	0
-
 /*
  * Do the traditional i8259 interrupt polling thing.  This is for the few
  * cases where no better interrupt acknowledge method is available and we