The fallback is used for cases when CONFIG_SERIAL_TAG defined, but the
eeprom is not used.
The fallback is useful for more than one CompuLab board, so move it to a
common location.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Reviewed-by: Tom Rini <trini@ti.com>

Extract the USB hub reset code to a common location where it can be
reused by other compulab boards.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Reviewed-by: Tom Rini <trini@ti.com>

Move board revision handling code to a common location
for further reuse.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Reviewed-by: Tom Rini <trini@ti.com>