MFC r266923:

  Ignore IIC_ENOADDR from iicbus_reset() as it only means we have a
  master-only controller.

  This fixes the iic bus scan with i2c(8) (on supported controllers).

  Tested with gpioiic(4).

MFC r267009:

  Remove the unnecessary i2c slave address assignment.

  The ti_i2c controller only works in the master mode and the i2c address
  passed on iicbus_reset() is used to set the controller slave address when
  operating as an i2c slave (which isn't currently supported).

  When talking to a slave, the slave address is correctly provided to
  ti_i2c_tranfer().