platform/chrome: cros_ec_lpc: Handle EC without CRS section

Fix logic to support GOOG0004 device without CRS section.
Instead of failing, assume there are not memory mapped EC registers.

Fixes: be4fccb5 ("platform/chrome: cros_ec_lpc: Support direct EC register memory access")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20250114202122.2352277-1-gwendal@chromium.org


Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>