Blackfin: drop unneeded asm/.gitignore

We don't create a include/asm/mach/ symlink anymore, so we don't need the
.gitignore for it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/include/asm/.gitignore b/arch/blackfin/include/asm/.gitignore
deleted file mode 100644
index 7858564..0000000
--- a/arch/blackfin/include/asm/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-+mach