can: m_can: Rename m_can_priv to m_can_classdev

Rename the common m_can_priv class structure to m_can_classdev as this
is more descriptive.

Acked-by: Wolfgang Grandegger <[email protected]>
Signed-off-by: Dan Murphy <[email protected]>
Acked-by: Faiz Abbas <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: Dan Murphy