uninative-tarball: Make stamp independent

The uninative tarball only contains nativesdk compoents. It should
not get regenerated when MACHINE changes for example. Currently its
sstate arch is also incorrect so changing SDKMACHINE results in other
variants being removed from the deploy directory.

This patch removes the target architecture dependencies so that
deploy artefacts can overlap and it doesn't continually rebuild. This
also fixes various autobuilder/release artefact issues we're having
as a result of these issues.

(From OE-Core rev: 6edd0b8dccc6e1e21f2ef87013e2e0a40d19b0d6)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/meta/uninative-tarball.bb

@@ -18,6 +18,9 @@ INHIBIT_DEFAULT_DEPS = "1"
 
 MULTIMACH_TARGET_SYS = "${SDK_ARCH}-nativesdk${SDK_VENDOR}-${SDK_OS}"
 PACKAGE_ARCH = "${SDK_ARCH}"
+PACKAGE_ARCHS = ""
+TARGET_ARCH = "none"
+TARGET_OS = "none"
 
 TOOLCHAIN_OUTPUTNAME ?= "${SDK_ARCH}-nativesdk-libc"
 
@@ -27,16 +30,19 @@ EXCLUDE_FROM_WORLD = "1"
 
 inherit meta
 inherit populate_sdk
+inherit nopackages
 
 deltask install
 deltask package
 deltask packagedata
+deltask populate_sysroot
 
 do_populate_sdk[stamp-extra-info] = "${SDKMACHINE}"
 
 SDK_DEPENDS += "patchelf-native"
 
 SDK_PACKAGING_FUNC = ""
+REAL_MULTIMACH_TARGET_SYS = "none"
 
 fakeroot create_sdk_files() {
 	cp ${COREBASE}/scripts/relocate_sdk.py ${SDK_OUTPUT}/${SDKPATH}/