Added a new compatible string "ti,am437x-ocp2scp" for OCP2SCP module.
This is needed since except for the OCP2SCP used in AM437x, SYNC2 value
in OCP2SCP TIMING should be changed whereas the default value is sufficient
in AM437x.

Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>