ARM: dts: sun8i-v3s: Add I2C1 PB pins description

I2C1 can be exposed through PB pins in addition to PE pins on the V3s.
Add the device-tree description for these pins.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20201031182137.1879521-4-contact@paulk.fr