modules: zcbor: Add config CONFIG_ZCBOR_MAX_STR_LEN

For use with zcbor_tstr_put_term() which needs a maximum string
length.

(cherry picked from commit ea4c12d)

Original-Signed-off-by: Øyvind Rønningstad <oyvind.ronningstad@nordicsemi.no>
GitOrigin-RevId: ea4c12d
Change-Id: I01747f0f9dc86ef93f0fd45e840ebbdc468779d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5240555
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Reviewed-by: Tristan Honscheid <honscheid@google.com>
Commit-Queue: Tristan Honscheid <honscheid@google.com>
Tested-by: Tristan Honscheid <honscheid@google.com>

modules/zcbor/Kconfig

@@ -33,4 +33,11 @@ config ZCBOR_ASSERT
 config ZCBOR_BIG_ENDIAN
 	def_bool BIG_ENDIAN
 
+config ZCBOR_MAX_STR_LEN
+	int "Default max length when calling zcbor_tstr_put_term()"
+	default 256
+	help
+	  This can be manually used if no other value is readily available, but
+	  using this is discouraged.
+
 endif # ZCBOR