net: dsa: microchip: perform the compatibility check for dev probed

This patch perform the compatibility check for the device after the chip
detect is done. It is to prevent the mismatch between the device
compatible specified in the device tree and actual device found during
the detect. The ksz9477 device doesn't use any .data in the
of_device_id. But the ksz8795_spi uses .data for assigning the regmap
between 8830 family and 87xx family switch. Changed the regmap
assignment based on the chip_id from the .data.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>