phy: core: Reword the comment specifying the units of max_link_rate to be Mbps

In some subsystems (eg. CAN, SPI), the max link rate supported can be less
than 1 Mbps and if the unit for max_link_rate is Mbps then it can't be
used. Therefore, leave the decision of units to be used, to the producer
and consumer.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20210510051006.11393-2-a-govindraju@ti.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>