CHROMIUM: Add #line to adc_npcx.c

Work around coreboot GCC preprocessor bug.

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

Change-Id: Idd5ea750a56a665f3512f84a45854bd787360f1d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5690458
Reviewed-by: Yuval Peress <peress@google.com>
Commit-Queue: Jeremy Bettis <jbettis@chromium.org>
Tested-by: Jeremy Bettis <jbettis@chromium.org>

drivers/adc/adc_npcx.c

@@ -4,6 +4,12 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/*
+ * TODO(b/272518464): Work around coreboot GCC preprocessor bug.
+ * #line marks the *next* line, so it is off by one.
+ */
+#line 12
+
 #define DT_DRV_COMPAT nuvoton_npcx_adc
 
 #include <assert.h>