tests: coverage: exclude the CODE UNREACHABLE of code coverage

1. Exclude the CODE UNREACHABLE line while generating coverage report.
2. Exclude the memory domain deprecated API when calculating code
coverage.

Signed-off-by: Enjia Mai <enjiax.mai@intel.com>
diff --git a/kernel/compiler_stack_protect.c b/kernel/compiler_stack_protect.c
index 2a0dc37..3c3abd1 100644
--- a/kernel/compiler_stack_protect.c
+++ b/kernel/compiler_stack_protect.c
@@ -37,7 +37,7 @@
 	/* Stack canary error is a software fatal condition; treat it as such.
 	 */
 	z_except_reason(K_ERR_STACK_CHK_FAIL);
-	CODE_UNREACHABLE;
+	CODE_UNREACHABLE; /* LCOV_EXCL_LINE */
 }
 
 /* Global variable */