can: mscan-mpc5xxx: fix broken support for the MPC5200

Due to an invalid "#ifdef CONFIG_PPC_MPC5200", the real clock setup
function was not called for the MPC5200.

Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>