Clean up bootloader project ASF integration code.

Bootloaders/DFU/asf.xml

@@ -117,7 +117,7 @@
 
 	<module type="application" id="lufa.bootloaders.dfu" caption="DFU Bootloader">
 		<info type="description" value="summary">
-		DFU Class Bootloader.
+		DFU Class Bootloader, capable of reprogramming a device using the Atmel FLIP or other AVR DFU programming software when plugged into a host.
 		</info>
 
 		<device-support-alias value="lufa_avr8"/>
@@ -129,10 +129,6 @@
 			<keyword value="USB Device"/>
 		</info>
 
-		<device-support-alias value="lufa_avr8"/>
-		<device-support-alias value="lufa_xmega"/>
-		<device-support-alias value="lufa_uc3"/>
-
 		<build type="include-path" value="."/>
 		<build type="c-source" value="BootloaderDFU.c"/>
 		<build type="header-file" value="BootloaderDFU.h"/>