Revert "watchdog: s3c2410_wdt: use exynos_get_pmu_regmap_by_phandle() for PMU regs"

This reverts commit 746f0770.

Now that we can register a SoC specific regmap with syscon using
of_syscon_register_regmap() api we can switch back to using
syscon_regmap_lookup_by_phandle() in the client drivers.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20241029191131.2329414-1-peter.griffin@linaro.org


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>