mac80211: remove useless patch

This patch was already applied upstream, linux/device.h gets included 2
lines above this change.

This was done in this commit:
https://git.kernel.org/cgit/linux/kernel/git/backports/backports.git/commit/?id=fd6bb301116d48c50722b0a4399e26ab0237e563

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 46202

package/kernel/mac80211/patches/004-backports_debugfs_fix.patch

@@ -1,10 +0,0 @@
---- a/backport-include/linux/debugfs.h
-+++ b/backport-include/linux/debugfs.h
-@@ -4,6 +4,7 @@
- #include <linux/version.h>
- #include <linux/device.h>
- #include <generated/utsrelease.h>
-+#include <linux/device.h>
- 
- #if defined(CONFIG_DEBUG_FS)
- struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,