ncurses_6: Improve installation

ncurses_6: Improve installation

As "install.libs" also installs header files, it is
redundant to also call "install.includes".
In fact, doing so can lead to a race, as both targets could
try to install the header files at the same time if running
parallel make. Obviously, with only calling "install.libs",
there is no race with "install.includes".
If there is no race, then the patch fix-include-files-race.patch
is no longer needed.

(From OE-Core rev: 8df2060a323acf2a2cc2bc4076623463039c46a6)

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>