gdb-cross-sdk: reconfigure before running oe_runmake configure-host

gdb-cross-sdk: reconfigure before running oe_runmake configure-host

so we have : configure then make configure-host which generates the
Makefile that we modify using sed to statically link the libs

Without this patch, we don't statically link libncurses, libtinfo
and libz which leads to :
/usr/local/angstrom/arm/bin/arm-angstrom-linux-gnueabi-gdb:
error while loading shared libraries: libtinfo.so.5:
cannot open shared object file: No such file or directory

when trying to use the toolchain.

Signed-off-by: Eric Bénard <eric@eukrea.com>
Acked-by: Khem Raj <raj.khem@gmail.com>
Acked-by: Tom Rini <tom_rini@mentor.com>