mfd: da9052: Store result from fault_log

Other sub-components (da9052-wdt) could use the result to determine
reboot cause. Expose the result by make it part of the da9052 structure.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20241210-da9052-wdt-v2-1-95a5756e9ac8@gmail.com


Signed-off-by: Lee Jones <lee@kernel.org>