binutils/elf2flt: Add CUSTOM version, CUSTOM_LOCATION config options, GetCustom

CUSTOM_LOCATION config options only presented in menuconfig if component
CUSTOM version selected.

Change elf2flt CT_ELF2FLT_VERSION from 'head' to 'cvs' if cvs selected in config

Also remove hardcoded 'cvs-' from elf2flt component name, used in CT_Extract,
CT_Patch and as the CT_SRC_DIR location for the configure stage.

Signed-off-by: "David Holsgrove" <david.holsgrove@xilinx.com>
[yann.morin.1998@free.fr: fix indentation, don't patch custom dir location]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <288db3721a37844defa5.1349931196@localhost.localdomain>
PatchWork-Id: 190789

hg