ARM64: dts: meson-axg: clean-up i2c nodes

Remove undocumented and unused "clk_i2c" clock name and the second
interrupt from i2c nodes of meson-axg platform. Those seems to have
been copy/pasted from the vendor kernel

Fixes: dc6f858e ("ARM64: dts: meson-axg: add I2C DT info for Meson-AXG SoC")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>