toolchain/gdb: Use correct folder name for ARC patches

Even though ARC tools were released as arc-2016.03
we have a little bit different version name for GDB.
That's because both Binutils and GDB come from the same
git repo but from different branches (and so different tags).

Also removing an extra patch that made its way into release.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

toolchain/gdb/patches/arc-2016.03/200-arc-fix-target-mask.patch

@@ -1,13 +0,0 @@
-diff --git a/bfd/config.bfd b/bfd/config.bfd
-index 5145d4a..a9c9c99 100644
---- a/bfd/config.bfd
-+++ b/bfd/config.bfd
-@@ -275,7 +275,7 @@ case "${targ}" in
-     targ_defvec=am33_elf32_linux_vec
-     ;;
- 
--  arc*-*-elf* | arc*-*-linux-uclibc*)
-+  arc*-*-elf* | arc*-*-linux-*)
-     targ_defvec=arc_elf32_le_vec
-     targ_selvecs=arc_elf32_be_vec
-     ;;