dt-bindings: rtc: Fix Xicor X1205 vendor prefix

The vendor for the Xircom X1205 RTC is not Xircom, but Xicor which was
acquired by Intersil.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250821215703.869628-1-robh@kernel.org


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>