freetype: install ft2build.h

Required for splashutils.
May be required for other programs too.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

libs/freetype/Makefile

@@ -58,6 +58,7 @@ define Build/InstallDev
 	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/bin/freetype-config $(2)/bin/
 	$(INSTALL_DIR) $(1)/usr/include
 	$(CP) $(PKG_INSTALL_DIR)/usr/include/freetype2 $(1)/usr/include/
+	$(CP) $(PKG_INSTALL_DIR)/usr/include/ft2build.h $(1)/usr/include/
 	$(INSTALL_DIR) $(1)/usr/lib
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libfreetype.{a,so*} $(1)/usr/lib/
 	$(INSTALL_DIR) $(1)/usr/lib/pkgconfig