sdk: Enable do_populate_sdk with multilibs

This patch enables building image based SDKs for multi-libbed images
e.g. lib32-core-image-minimal and so on. Change the path to nativesdk
tools to use recipe-sysroot since thats where the nativesdk components
are installed and it will need access to qemu wrappers during build for
processing intercepts

[YOCTO #14444]

(From OE-Core rev: 3d18d1924ff0dcf8788ee856e3f056e77db8f920)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 6196a785eababb040ee1dee9f33cb6d6dad77eef)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/multilib.bbclass

@@ -105,7 +105,6 @@ python __anonymous () {
         d.setVar("LINGUAS_INSTALL", "")
         # FIXME, we need to map this to something, not delete it!
         d.setVar("PACKAGE_INSTALL_ATTEMPTONLY", "")
-        bb.build.deltask('do_populate_sdk', d)
         bb.build.deltask('do_populate_sdk_ext', d)
         return
 }

meta/classes/populate_sdk_base.bbclass

@@ -66,7 +66,7 @@ python () {
 
 SDK_RDEPENDS = "${TOOLCHAIN_TARGET_TASK} ${TOOLCHAIN_HOST_TASK}"
 SDK_DEPENDS = "virtual/fakeroot-native ${SDK_ARCHIVE_DEPENDS} cross-localedef-native nativesdk-qemuwrapper-cross ${@' '.join(["%s-qemuwrapper-cross" % m for m in d.getVar("MULTILIB_VARIANTS").split()])} qemuwrapper-cross"
-PATH_prepend = "${STAGING_DIR_HOST}${SDKPATHNATIVE}${bindir}/crossscripts:${@":".join(all_multilib_tune_values(d, 'STAGING_BINDIR_CROSS').split())}:"
+PATH_prepend = "${WORKDIR}/recipe-sysroot/${SDKPATHNATIVE}${bindir}/crossscripts:${@":".join(all_multilib_tune_values(d, 'STAGING_BINDIR_CROSS').split())}:"
 SDK_DEPENDS += "nativesdk-glibc-locale"
 
 # We want the MULTIARCH_TARGET_SYS to point to the TUNE_PKGARCH, not PACKAGE_ARCH as it