patches/binutils/2.20: make patches appliable

Fix filenames in patch files for binutils-2.20.
Some patch files were only usable with patch argument '-p0'.
Fix the diff context to match 2.20 release.

Signed-off-by: Frederic Roussel <fr.frasc@gmail.com>

 # x86 specific options

 config ARCH_x86

     select ARCH_USE_MMU

     select ARCH_SUPPORT_ARCH

     select ARCH_SUPPORT_CPU

     select ARCH_SUPPORT_TUNE

     help

       The x86 architecture, as defined by:

         http://www.intel.com/