debug/gdb: Add CUSTOM version and CUSTOM_LOCATION config options and GetCustom

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

Signed-off-by: "David Holsgrove" <david.holsgrove@xilinx.com>
[yann.morin.1998@free.fr: don't patch custom dir location]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <9ea1b5021fc77582867f.1349931197@localhost.localdomain>
PatchWork-Id: 190791

CT_EXPERIMENTAL=y

CT_LOCAL_TARBALLS_DIR="${HOME}/src"

CT_SAVE_TARBALLS=y

CT_LOG_EXTRA=y

CT_ARCH_ARCH="i686"

CT_ARCH_x86=y

CT_TARGET_VENDOR="pc"

CT_KERNEL_mingw32=y

CT_BINUTILS_V_2_21_1a=y

CT_BINUTILS_PLUGINS=y

CT_CC_V_4_4_5=y

CT_CC_LANG_CXX=y

CT_MINGW_DIRECTX=y

CT_MINGW_OPENGL=y

CT_MINGW_PDCURSES=y

CT_MINGW_GNURX=y

CT_GMP_V_4_3_2=y

CT_MPFR_V_2_4_1=y

CT_PPL_V_0_10_2=y

CT_CLOOG_V_0_15_10=y