populate_sdk_ipk.bbclass: Ensure the correct environment is setup for postinstalls
Without this, various postinstalls get run with incorrect environments
leading to various failures when building the toolchains.
This adds some duplication and some variables we'd be better off
removing. It does unbreak the SDK ipk code for now though. This needs
revisiting.
(From OE-Core rev:
c5e6a533eab2f5af4a52d22f8efe5b49b77cd26c)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Joshua Lock <josh@linux.intel.com>
