dt-bindings: watchdog: samsung-wdt: Drop S3C2410

Samsung S3C2410 SoC was removed from Linux kernel in the
commit 61b7f892 ("ARM: s3c: remove all s3c24xx support"), in January
2023.  There are no in-kernel users of samsung,s3c2410-wdt compatible
anymore and platform is so old, that there should be no out-of-tree
users.  If such existed, they would have enough of time to object
dropping Samsung S3C2410 SoC removal from the kernel (which did not
happen).

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>