i2c: mlxbf: add multi slave functionality

Support the multi slave functionality which enables the BlueField
to be registered at up to 16 i2c slave addresses.

Reviewed-by: Khalil Blaiech <[email protected]>
Signed-off-by: Asmaa Mnebhi <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>

Author: Asmaa Mnebhi