am33xx/omap: Allow cache enable for all Sitara/OMAP

Enable the cache for all devices, unless CONFIG_SYS_DCACHE_OFF is defined.
This speeds up the Beaglebone Black boot considerable.

(Tested only on Beaglebone Black with SD card boot)

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv7/omap-common/Makefile b/arch/arm/cpu/armv7/omap-common/Makefile
index 5f5132f..7695e16 100644
--- a/arch/arm/cpu/armv7/omap-common/Makefile
+++ b/arch/arm/cpu/armv7/omap-common/Makefile
@@ -22,6 +22,10 @@
 obj-$(CONFIG_SCSI_AHCI_PLAT) += sata.o
 endif
 
+ifeq ($(CONFIG_SYS_DCACHE_OFF),)
+obj-y	+= omap-cache.o
+endif
+
 ifeq ($(CONFIG_OMAP34XX),)
 obj-y	+= boot-common.o
 obj-y	+= lowlevel_init.o