Correct a typo in the vin-supply property.  The input supply is
always-on, so this mistake doesn't affect whether the supply is actually
enabled correctly.

Fixes: fc702ed4 ("arm64: dts: rockchip: Add dts for Leez RK3399 P710 SBC")
Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20211102182908.3409670-3-john@metanate.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>