power: reset: brcmstb: Use syscon_regmap_lookup_by_phandle_args() helper

Simplify probe by fetching the regmap and its arguments in one call.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240610142836.168603-3-afd@ti.com


Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>