powerpc/mpic: Add get_version API both for internal and external use

MPIC version is useful information for both mpic_alloc() and mpic_init().
The patch provide an API to get MPIC version for reusing the code.
Also, some other IP block may need MPIC version for their own use.
The API for external use is also provided.

Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h
index c0f9ef9..ea6bf72 100644
--- a/arch/powerpc/include/asm/mpic.h
+++ b/arch/powerpc/include/asm/mpic.h
@@ -393,6 +393,9 @@
 #define	MPIC_REGSET_STANDARD		MPIC_REGSET(0)	/* Original MPIC */
 #define	MPIC_REGSET_TSI108		MPIC_REGSET(1)	/* Tsi108/109 PIC */
 
+/* Get the version of primary MPIC */
+extern u32 fsl_mpic_primary_get_version(void);
+
 /* Allocate the controller structure and setup the linux irq descs
  * for the range if interrupts passed in. No HW initialization is
  * actually performed.