debug/gdb: chmod ncurses files to u+w

The ncurses-5.7 tarball contains only RO files.
We have to chmod them u+w.

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

reporter_name="Yann E. MORIN"

reporter_url="http://ymorin.is-a-geek.org/projects/crosstool"

reporter_comment="EXPERIMENTAL MIPS-64 n64 toolchain."