ARM: DRA722: Add ID detect for Silicon Rev 2.0

Silicon Rev 2.0 is a minor variant of Rev 1.0. Rev 2.0 is an incremental revision
with various fixes including the following:
    - Reset logic fixes
    - Few asymmetric aging logic fixes
    - Ethernet speed fixes
    - EDMA fixes for McASP

Signed-off-by: Vishal Mahaveer <vishalm@ti.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>