omap: mailbox: Add build specific changes to support omap mailbox

This patch adds changes to the build related files of mailbox
driver
Signed-off-by: NC A Subramaniam <subramaniam.ca@ti.com>
Signed-off-by: NRamesh Gupta G <grgupta@ti.com>
Acked-by: NHiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/Makefile

@@ -44,6 +44,9 @@ obj-$(CONFIG_ARCH_OMAP4)		+= cm4xxx.o
 obj-$(CONFIG_ARCH_OMAP2)		+= clock24xx.o
 obj-$(CONFIG_ARCH_OMAP3)		+= clock34xx.o
 
+obj-$(CONFIG_OMAP_MBOX_FWK)		+= mailbox_mach.o
+mailbox_mach-objs			:= mailbox.o
+
 iommu-y					+= iommu2.o
 iommu-$(CONFIG_ARCH_OMAP3)		+= omap3-iommu.o