bitbake.conf: use TUNE_PKGARCH instead of TARGET_ARCH in SDK_NAME
* also use weak assignment for SDK_NAME_PREFIX as suggested by khem
* TUNE_PKGARCH is not 100% right too, because such SDK image usually has few
machine specific packages included (e.g. base-files, securetty, opkg configs)
but those are not important for SDK users so it's better to have one SDK for
whole e.g. armv7a-vfp-neon then 6 SDK for each machine which would work the
same.
You can see diff between crespo and om-gta04 SDK here:
http://build.shr-project.org/shr-core/sdk/oecore-i686-armv7a-vfp-neon-toolchain-efl-crespo-om-gta04.diff
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
