Add DCAN support for AM437x GP EVM with both DCAN instances.

[Roger Q] Updated output pin to not use pull up.
Signed-off-by: NMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: NGeorge Cherian <george.cherian@ti.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>