Similarly to commit 8cf1b512 for SPI, the Rpi4 has more i2c busses to offer
This change allows klipper to use up to I2c bus 6
/boot/configtxt
dtparam=i2c_arm=on
dtoverlay=i2c6
and
pi@fluiddpi:~ $ ls -1 /dev/i2c*
/dev/i2c-1
/dev/i2c-6
Signed-off-by: Sylvain Dansereau <brutus_dansereau@hotmail.com>