cc/gcc: remove 'sub-level' version form symbols

Now we use defconfig files to store the samples, we have to be a bit more
conservatives in the symbols names, so as to avoid gigantic version bumps
when updating sub-level versions from a package.

For example (using fictitious versions):
- in crosstool-NG 1.17.0, we choose:
- latest gcc is gcc-linaro-4.7-2012.10, which is the default for the
choice in the menuconfig
- gcc-linaro-4.6-2012.10 is selected
- so, sample has an explicit symbol for the selected gcc version, as it
is not the default
- we update to crosstool-NG 1.18.0:
- latest gcc version is gcc-linaro-4.7-2013.01
- gcc-linaro-46 has been updated to gcc-linaro-4.6-2013.01
- as the sample now has no *valid* symbol to set the gcc version, the
default is used, while we would have expected to still use the 4.6
release from linaro, not the 4.7

Get rid of sub-level (ie. the third digit sequence in versions) from the
symbols for linaro versions.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 # Build script for libtool

 CT_LIBTOOL_VERSION=2.2.6b

 do_companion_tools_libtool_get() {

     CT_GetFile "libtool-${CT_LIBTOOL_VERSION}" \

                {ftp,http}://ftp.gnu.org/gnu/libtool

 }

 do_companion_tools_libtool_extract() {

     CT_Extract "libtool-${CT_LIBTOOL_VERSION}"

     CT_DoExecLog ALL chmod -R u+w "${CT_SRC_DIR}/libtool-${CT_LIBTOOL_VERSION}"

     CT_Patch "libtool" "${CT_LIBTOOL_VERSION}"

 }

 do_companion_tools_libtool_build() {

     CT_DoStep EXTRA "Installing libtool"

     mkdir -p "${CT_BUILD_DIR}/build-libtool"

     CT_Pushd "${CT_BUILD_DIR}/build-libtool"

     CT_DoExecLog CFG \

     "${CT_SRC_DIR}/libtool-${CT_LIBTOOL_VERSION}/configure" \

         --prefix="${CT_BUILDTOOLS_PREFIX_DIR}"

     CT_DoExecLog ALL make

     CT_DoExecLog ALL make install

     CT_Popd

     CT_EndStep

 }