kconfig: shell: fix incorrect shell stack size for Thread

Shell stack size is too low for OpenThread without joiner
functionality, causing overflow.

In this commit, the value of stack size is not changed.
Incorrect assigning of value for opentrhead with
no joiner functionality has been removed.

(cherry picked from commit 9be8310)

Original-Signed-off-by: Maciej Baczmanski <maciej.baczmanski@nordicsemi.no>
GitOrigin-RevId: 9be8310
Change-Id: I29812883bcacd9962225cb3cf11b3e2a27113f5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5356060
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Commit-Queue: Tristan Honscheid <honscheid@google.com>
Tested-by: Tristan Honscheid <honscheid@google.com>
Reviewed-by: Tristan Honscheid <honscheid@google.com>

subsys/shell/Kconfig

@@ -40,9 +40,8 @@ endif
 
 config SHELL_STACK_SIZE
  int "Shell thread stack size"
- default 3168 if OPENTHREAD_SHELL && OPENTHREAD_JOINER
+ default 3168 if OPENTHREAD_SHELL
  default 3072 if 64BIT
- default 2616 if OPENTHREAD_SHELL
  default 2048 if MULTITHREADING
  default 0 if !MULTITHREADING
  help