core/pkg-kconfig: extract package before using kconfig fragments

Kconfig fragments may be present in the package, so we need to extract
and patch it before we can use the fragments.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Floris Bos <bos@je-eigen-domein.nl>
Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/pkg-kconfig.mk

@@ -37,9 +37,9 @@ $(2)_KCONFIG_OPTS ?=
 $(2)_KCONFIG_FIXUP_CMDS ?=
 $(2)_KCONFIG_FRAGMENT_FILES ?=
 
-# The config file could be in-tree, so before depending on it the package should
-# be extracted (and patched) first
-$$($(2)_KCONFIG_FILE): | $(1)-patch
+# The config file as well as the fragments could be in-tree, so before
+# depending on them the package should be extracted (and patched) first
+$$($(2)_KCONFIG_FILE) $$($(2)_KCONFIG_FRAGMENT_FILES): | $(1)-patch
 
 # The specified source configuration file and any additional configuration file
 # fragments are merged together to .config, after the package has been patched.