powerpc/85xx: fixup flexcan device tree clock-frequency

powerpc/85xx: fixup flexcan device tree clock-frequency

Make the fixup matchable with dts and kernel.  Update the compatible from
"fsl,flexcan-v1.0" to "fsl,p1010-flexcan" and Change the "clock-freq"
property to "clock-frequency".  We also change flexcan frequency from
CCB-clock to CCB-clock/2 according to P1010 spec.

We now keep the old interfaces to make previous kernel work. They should
be removed in the future.

Signed-off-by: Jia Hongtao <B38951@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>