meta-zephyr-sdk: Enable cross compilation

This commit enables cross compilation of the meta-zephyr-sdk by
allowing the host machine variable (MACHINE) to be overridden when
calling the build script.

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

meta-zephyr-sdk/scripts/meta-zephyr-sdk-build.sh

@@ -27,7 +27,7 @@ TOOLCHAINS="${META_ZEPHYR_SDK_SOURCE}/scripts/toolchains"
 META_DOWNLOADS=${META_DOWNLOADS:-"$META_POKY_SOURCE/downloads"}
 META_SSTATE=${SSTATE_LOCATION:-"$META_POKY_SOURCE/sstate"}
 
-MACHINE=$(uname -m)
+MACHINE=${MACHINE:-$(uname -m)}
 
 if [ ! -d $META_ZEPHYR_SDK_SOURCE ] ; then
 	echo "ERROR: could not find $META_ZEPHYR_SDK_SOURCE"