build: remove broken dependency of metadata on toplevel .config variables

Instead of relying on .config symbols for metadata, alter the DEFAULT
variable of affected packages. Fixes enabling opkg vs apk among others.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry picked from commit 44598c233d)

package/system/apk/Makefile

@@ -36,6 +36,7 @@ define Package/apk-mbedtls
   $(Package/apk/default)
   TITLE += (mbedtls)
   DEPENDS +=+libmbedtls
+  DEFAULT:=y if USE_APK
   VARIANT:=mbedtls
   DEFAULT_VARIANT:=1
   CONFLICTS:=apk-openssl

package/system/opkg/Makefile

@@ -39,6 +39,7 @@ define Package/opkg
   CATEGORY:=Base system
   TITLE:=opkg package manager
   DEPENDS:=+uclient-fetch +libpthread +libubox
+  DEFAULT:=y if !USE_APK
   URL:=$(PKG_SOURCE_URL)
   MENU:=1
 endef

package/system/procd/Makefile

@@ -50,6 +50,7 @@ define Package/procd
   $(call Package/procd/Default)
   VARIANT:=default
   CONFLICTS:=procd-selinux
+  DEFAULT:=y if !SELINUX
 endef
 
 define Package/procd-selinux
@@ -58,6 +59,7 @@ define Package/procd-selinux
   TITLE += with SELinux support
   PROVIDES:=procd
   VARIANT:=selinux
+  DEFAULT:=y if SELINUX
 endef
 
 define Package/procd-ujail
@@ -73,6 +75,7 @@ define Package/procd-seccomp
   CATEGORY:=Base system
   DEPENDS:=@SECCOMP +libubox +libblobmsg-json
   TITLE:=OpenWrt process seccomp helper + utrace
+  DEFAULT:=y if SECCOMP
 endef
 
 define Package/uxc

package/utils/busybox/Makefile

@@ -56,6 +56,7 @@ define Package/busybox
   $(call Package/busybox/Default)
   CONFLICTS:=busybox-selinux
   VARIANT:=default
+  DEFAULT:=y if !SELINUX
 endef
 
 define Package/busybox-selinux
@@ -64,6 +65,7 @@ define Package/busybox-selinux
   DEPENDS += +libselinux
   VARIANT:=selinux
   PROVIDES:=busybox
+  DEFAULT:=y if SELINUX
 endef
 
 define Package/busybox/description