busybox: preserve ncurses progs/tools

The ncurses package installs a full version of clear and reset(tset)
tools.  Preserve these by disabling the options in the busybox config
file.  This removes the need for ncurses to depend on busybox for solely
ordering of target install.

This commit resolves the following python circular dependency with python.
busybox -> libselinux -> python3 -> ncurses -> busybox

Fixes:
http://autobuild.buildroot.net/results/db1/db1e6f3054092fc5576ccab8e04a3b9d74ca9a8c/

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
[Thomas: minor tweaks.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/busybox/busybox.mk

@@ -148,6 +148,17 @@ define BUSYBOX_MUSL_TWEAKS
 endef
 endif
 
+ifeq ($(BR2_PACKAGE_NCURSES_TARGET_PROGS),y)
+# Ncurses package overlaps:
+#     /usr/bin/clear
+#     /usr/bin/reset -> /usr/bin/tset (symlink)
+#
+define BUSYBOX_DISABLE_NCURSES_PROGS
+	$(call KCONFIG_DISABLE_OPT,CONFIG_CLEAR,$(BUSYBOX_BUILD_CONFIG))
+	$(call KCONFIG_DISABLE_OPT,CONFIG_RESET,$(BUSYBOX_BUILD_CONFIG))
+endef
+endif
+
 define BUSYBOX_INSTALL_UDHCPC_SCRIPT
 	if grep -q CONFIG_UDHCPC=y $(@D)/.config; then \
 		$(INSTALL) -m 0755 -D package/busybox/udhcpc.script \
@@ -229,6 +240,7 @@ define BUSYBOX_KCONFIG_FIXUP_CMDS
 	$(BUSYBOX_SET_WATCHDOG)
 	$(BUSYBOX_SET_SELINUX)
 	$(BUSYBOX_MUSL_TWEAKS)
+	$(BUSYBOX_DISABLE_NCURSES_PROGS)
 endef
 
 define BUSYBOX_CONFIGURE_CMDS

package/ncurses/ncurses.mk

@@ -29,11 +29,6 @@ NCURSES_CONF_OPTS = \
 	$(if $(BR2_PACKAGE_NCURSES_TARGET_PROGS),,--without-progs) \
 	--without-manpages
 
-# Install after busybox for the full-blown versions
-ifeq ($(BR2_PACKAGE_BUSYBOX),y)
-NCURSES_DEPENDENCIES += busybox
-endif
-
 ifeq ($(BR2_STATIC_LIBS),y)
 NCURSES_CONF_OPTS += --without-shared --with-normal
 else ifeq ($(BR2_SHARED_LIBS),y)