populate_sdk_base: allow SDK path of various level

In the previous version, tar extraction use the --strip-component
option with "4" hard coded value.
If we set another SDKPATH, with a different depth, the sdk installation
fails.

This patch computes the level from the SDKPATH value.

(From OE-Core rev: 7aee4e9438755c230e1399bd5226d6c8e7fcca31)

Signed-off-by: Fabien Proriol <fabien.proriol@jdsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/populate_sdk_base.bbclass

@@ -119,6 +119,7 @@ fakeroot create_shar() {
 #!/bin/bash
 
 DEFAULT_INSTALL_DIR="${SDKPATH}"
+COMPONENTS_LEN=$(echo ".${SDKPATH}" | sed "s/\// /g" | wc -w)
 
 printf "Enter target directory for SDK (default: $DEFAULT_INSTALL_DIR): "
 read target_sdk_dir
@@ -155,7 +156,7 @@ fi
 payload_offset=$(($(grep -na -m1 "^MARKER:$" $0|cut -d':' -f1) + 1))
 
 printf "Extracting SDK..."
-tail -n +$payload_offset $0| tar xj --strip-components=4 -C $target_sdk_dir
+tail -n +$payload_offset $0| tar xj --strip-components=$COMPONENTS_LEN -C $target_sdk_dir
 echo "done"
 
 printf "Setting it up..."