CHROUMIUM: Add #line to shell.c

Work around coreboot GCC preprocessor bug.

BUG=b:272518464
TEST=BOARD=myst; zmake build -c $BOARD &&
./util/find_non_exec_lines.py build/zephyr/$BOARD/output/zephyr.info

Change-Id: Iac0e47b278fb3a323e06c08ab443ffd4ee0223b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5684208
Auto-Submit: Jeremy Bettis <jbettis@chromium.org>
Tested-by: Jeremy Bettis <jbettis@chromium.org>
Reviewed-by: Tristan Honscheid <honscheid@google.com>
Commit-Queue: Jeremy Bettis <jbettis@chromium.org>

subsys/shell/shell.c

@@ -23,6 +23,7 @@
 #include "shell_vt100.h"
 #include "shell_wildcard.h"
 
+#line 27
 /* 2 == 1 char for cmd + 1 char for '\0' */
 #if (CONFIG_SHELL_CMD_BUFF_SIZE < 2)
  #error too small CONFIG_SHELL_CMD_BUFF_SIZE