omap3_beagle: replace uImage.beagle with generic uImage

e682930867f7dfc4a01784fe452fad9e962d65a
(BeagleBoard: config: use uImage.beagle for tftp)

Introduced uImage.beagle which does not happen to be default output
file of Linux kernel build make uImage (output is uImage).

So, replace uImage.beagle with uImage

Signed-off-by: Nishanth Menon <nm@ti.com>
diff --git a/include/configs/omap3_beagle.h b/include/configs/omap3_beagle.h
index 8992c35..a5cd66d 100644
--- a/include/configs/omap3_beagle.h
+++ b/include/configs/omap3_beagle.h
@@ -194,7 +194,7 @@
 	"loadaddr=0x80200000\0" \
 	"rdaddr=0x81000000\0" \
 	"usbtty=cdc_acm\0" \
-	"bootfile=uImage.beagle\0" \
+	"bootfile=uImage\0" \
 	"console=ttyO2,115200n8\0" \
 	"mpurate=auto\0" \
 	"buddy=none\0" \