e2fsprogs: disable e4defrag on avr32

The fallocate syscall is not available on avr32. This is needed by the e4defrag
utility, so we disable this on avr32.

Fixes build failures such as the following.

  http://autobuild.buildroot.net/results/dcb/dcb4e5c6981a9299a2eb18e325d4de621846afdb/

Signed-off-by: Simon Dawson <spdawson@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/e2fsprogs/Config.in

@@ -49,6 +49,7 @@ config BR2_PACKAGE_E2FSPROGS_E2UNDO
 
 config BR2_PACKAGE_E2FSPROGS_E4DEFRAG
 	bool "e4defrag"
+	depends on !BR2_avr32 # fallocate not implemented
 
 config BR2_PACKAGE_E2FSPROGS_FILEFRAG
 	bool "filefrag"