watchdog: aspeed: fix 64-bit division

On 32-bit architectures, the new calculation causes a build failure:

ld.lld-21: error: undefined symbol: __aeabi_uldivmod

Since neither value is ever larger than a register, cast both
sides into a uintptr_t.

Fixes: 5c03f9f ("watchdog: aspeed: Update bootstatus handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20250314160248.502324-1-arnd@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Author: arndb

drivers/watchdog/aspeed_wdt.c

@@ -254,7 +254,7 @@ static void aspeed_wdt_update_bootstatus(struct platform_device *pdev,
 
 	if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,ast2400-wdt")) {
 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-		idx = ((intptr_t)wdt->base & 0x00000fff) / resource_size(res);
+		idx = ((intptr_t)wdt->base & 0x00000fff) / (uintptr_t)resource_size(res);
 	}
 
 	scu_base = syscon_regmap_lookup_by_compatible(scu.compatible);