can: flexcan: disable bus error interrupts for the i.MX6q

This patch adds some Flexcan version info and removes the feature flag
FLEXCAN_HAS_BROKEN_ERR_STATE for the i.MX6Q. It also has the line [TR]WRN_INT
properly connected.

Cc: Hui Wang <jason77.wang@gmail.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
[mkl: convert to incremental patch]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>