net: dsa: microchip: dcb: rename IPV to IPM

net: dsa: microchip: dcb: rename IPV to IPM

IPV is added and used term in 802.1Qci PSFP and merged into 802.1Q (from
802.1Q-2018) for another functions.

Even it does similar operation holding temporal priority value
internally (as it is named), because KSZ datasheet doesn't use the term
of IPV (Internal Priority Value) and avoiding any confusion later when
PSFP is in the Linux world, it is better to rename IPV to IPM (Internal
Priority Mapping).

In addition, LAN937x documentation already use IPV for 802.1Qci PSFP
related functionality.

Suggested-by: Woojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Woojung Huh <woojung.huh@microchip.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240510053828.2412516-2-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>