arm: dts: imx[35]*: declare flexcan devices to be compatible to imx25's flexcan

Commit d50f4630 ("arm: dts: Remove p1010-flexcan compatible from imx
series dts") removed the fallback compatible "fsl,p1010-flexcan" from
the imx device trees. As the flexcan cores on i.MX25, i.MX35 and i.MX53
are identical, introduce the first as fallback for the two latter ones.

Fixes: d50f4630 ("arm: dts: Remove p1010-flexcan compatible from imx series dts")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: linux-stable <stable@vger.kernel.org> # >= v4.16
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>