dts: riscv: spacemit: k3: Add i2c nodes

dts: riscv: spacemit: k3: Add i2c nodes

Populate all I2C devicetree nodes for SpacemiT K3 SoC. The controller of
i2c3 is reserved for secure domain, and not available from Linux. The
controller of i2c7 simply doesn't exist from hardware perspective, as
vendor directly name the i2c controller used for PMIC as i2c8.

Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Link: https://lore.kernel.org/r/20260327-02-k3-i2c-v2-1-2119c0918868@kernel.org
Signed-off-by: Yixun Lan <dlan@kernel.org>