arm64: dts: allwinner: a100: Update I2C controller fallback

The I2C controllers in the A100 SoC are newer-generation hardware
which includes an offload engine. Signify that by including the
allwinner,sun8i-v536-i2c fallback compatible, as V536 is the first
SoC with this generation of I2C controller.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220702052544.31443-2-samuel@sholland.org