powerpc/mpic: Save computed phys_addr for board-specific code

The MPIC code can already perform an automatic OF address translation
step as part of mpic_alloc(), but several boards need to use that base
address when they perform mpic_assign_isu().

The easiest solution is to save the computed physical address into the
"struct mpic" for later use by the board code.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/mpic.h

@@ -293,6 +293,9 @@ struct mpic
 	/* Register access method */
 	enum mpic_reg_type	reg_type;
 
+	/* The physical base address of the MPIC */
+	phys_addr_t paddr;
+
 	/* The various ioremap'ed bases */
 	struct mpic_reg_bank	gregs;
 	struct mpic_reg_bank	tmregs;