Makefile: also check for ncurses6

Note some cross-compilers might not install the ncurses config scripts
and only the pkg-config files, but at least the atari SDK from NS does.

For others it might be required to check for the .pc files first.

Makefile

@@ -9,7 +9,13 @@ PREFIX ?= /usr/local
 INSTALLPATH ?= ${DESTDIR}${PREFIX}/bin
 MANPATH ?= ${DESTDIR}${PREFIX}/share/man/man1
 
-ifeq ($(shell sh -c 'which ncurses5-config>/dev/null 2>/dev/null && echo y'), y)
+ifeq ($(shell sh -c 'which ncurses6-config>/dev/null 2>/dev/null && echo y'), y)
+	CFLAGS += -Wall -g $$(ncurses6-config --cflags)
+	LDFLAGS += $$(ncurses6-config --libs)
+else ifeq ($(shell sh -c 'which ncursesw6-config>/dev/null 2>/dev/null && echo y'), y)
+		CFLAGS += -Wall -g $$(ncursesw6-config --cflags)
+		LDFLAGS += $$(ncursesw6-config --libs)
+else ifeq ($(shell sh -c 'which ncurses5-config>/dev/null 2>/dev/null && echo y'), y)
 	CFLAGS += -Wall -g $$(ncurses5-config --cflags)
 	LDFLAGS += $$(ncurses5-config --libs)
 else ifeq ($(shell sh -c 'which ncursesw5-config>/dev/null 2>/dev/null && echo y'), y)