[MIPS] Fix the build error of Wind River PPMC board, rewrite irq code to C

 o Fix the build error Wind River PPMC board caused by the change of
   plat_setup hook interface.
 o Rewrite first level interrupt dispatch code to C.

Signed-off-by: Rongkai.Zhan <rongkai.zhan@windriver.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 35e038a..3fa67af 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -358,7 +358,7 @@
 	  board.
 
 config WR_PPMC
-	bool "Support for Wind River PPMC board"
+	bool "Wind River PPMC board"
 	select IRQ_CPU
 	select BOOT_ELF32
 	select DMA_NONCOHERENT