[MIPS] Define MIPS_CPU_IRQ_BASE in generic header

The irq_base for {mips,rm7k,rm9k}_cpu_irq_init() are constant on all
platforms and are same value on most platforms (0 or 16, depends on
CONFIG_I8259).  Define them in asm-mips/mach-generic/irq.h and make
them customizable.  This will save a few cycle on each CPU interrupt.

A good side effect is removing some dependencies to MALTA in generic
SMTC code.

Although MIPS_CPU_IRQ_BASE is customizable, this patch changes irq
mappings on DDB5477, EMMA2RH and MIPS_SIM, since really customizing
them might cause some header dependency problem and there seems no
good reason to customize it.  So currently only VR41XX is using custom
MIPS_CPU_IRQ_BASE value, which is 0 regardless of CONFIG_I8259.

Testing this patch on those platforms is greatly appreciated.  Thank
you.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-mips/mach-mips/irq.h b/include/asm-mips/mach-mips/irq.h
index e994b0c01227..9b9da26683c2 100644
--- a/include/asm-mips/mach-mips/irq.h
+++ b/include/asm-mips/mach-mips/irq.h
@@ -4,4 +4,6 @@
 
 #define NR_IRQS 256
 
+#include_next <irq.h>
+
 #endif /* __ASM_MACH_MIPS_IRQ_H */