ARM: OMAP2+: Enable ARCH_MULTIPLATFORM support

Flip on multiplatform support for omap2+.

No changes to omap2plus_defconfig needed, but please note
that you may need to update your custom config files to
make sure you have:

CONFIG_ARCH_MULTIPLATFORM=y
CONFIG_ARCH_MULTI_V7=y
CONFIG_ARCH_OMAP2PLUS=y

And may need CONFIG_ARCH_MULTI_V6=y if booting omap2 boards.

Cc: Russell King <linux@arm.linux.org.uk>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 947cafe..65fb6fb 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -2,6 +2,9 @@
 # Makefile for the linux kernel.
 #
 
+ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \
+	-I$(srctree)/arch/arm/plat-omap/include
+
 # Common support
 obj-y := id.o io.o control.o mux.o devices.o fb.o serial.o gpmc.o timer.o pm.o \
 	 common.o gpio.o dma.o wd_timer.o display.o i2c.o hdq1w.o omap_hwmod.o \