ncurses: Convert to BBCLASSEXTEND

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

meta/packages/ncurses/ncurses-native_5.4.bb

@@ -1,3 +0,0 @@
-require ncurses_${PV}.bb
-inherit native
-DEPENDS = ""

meta/packages/ncurses/ncurses-nativesdk_5.4.bb

@@ -1,2 +0,0 @@
-require ncurses_${PV}.bb
-inherit nativesdk

meta/packages/ncurses/ncurses.inc

@@ -3,6 +3,7 @@ HOMEPAGE = "http://www.gnu.org/software/ncurses/ncurses.html"
 LICENSE = "MIT"
 SECTION = "libs"
 DEPENDS = "ncurses-native"
+DEPENDS_virtclass-native = ""
 PACKAGES_prepend = "ncurses-tools "
 PACKAGES_append = " ncurses-terminfo"
 FILES_ncurses_append = " ${datadir}/tabset"
@@ -99,3 +100,5 @@ pkg_prerm_ncurses-tools () {
 		update-alternatives --remove reset reset.${PN}
 	fi
 }
+
+BBCLASSEXTEND = "native nativesdk"