ncurses: Copy terminfo for 'screen-256color' terminal

Tmux uses 256 color version of 'screen' terminfo by default, so copy
corresponding file to support that usecase.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/ncurses/ncurses.mk

@@ -52,6 +52,7 @@ NCURSES_TERMINFO_FILES = \
 	p/putty \
 	p/putty-vt100 \
 	s/screen \
+	s/screen-256color \
 	v/vt100 \
 	v/vt100-putty \
 	v/vt102 \