[oe] [PATCH 0/8][v3] Make multi-machine toolchains to co-exist (revised again)

[Khem Raj]

Hi

Following series of patches are for making multi-machine toolchains co-exist with
new cross staging for toolchain.

It changes the toolchain triplet from ${TARGET_ARCH}-${VENDOR}-${OS} to 
${TARGET_ARCH}-${CPU_SUB_TARGET}_${VENDOR}-OS

which means that a toolchain for armv7 is called arm-v7a_oe-linux-gnueabi-*
and for armv5te its called arm-v5te_oe-linux-gnueabi-*

They can coexist in same native sysroot. The symlinks would mean that
gcc will not accidently mix the assemblers or linkers.

MULTIMACH-* is not needed anymore as the TARGET_SYS is distinct enough
to serve same purpose.

I have booted a minimal-image on qemuarm qemuppc and qemumips successfully. The build for 
beagleboard native-sdk-image completed too.

Thanks
-Khem