Remove useless target/arm directory

target/Makefile.in

@@ -9,7 +9,6 @@ include target/generic/Makefile.in
 # this eventually adds the kernel target to TARGETS:
 include target/device/Makefile.in
 include target/x86/Makefile.in
-include target/arm/Makefile.in
 include target/powerpc/Makefile.in
 # and finally build the filesystems/tarballs
 include target/*/*.mk

target/arm/Makefile.in

@@ -1 +0,0 @@
--include target/arm/*/*.mk