Davinci: allow SOCs based on other ARM CPUs

Preliminary modification prior to adding support for TNETV107X based on
ARM1176.  This change allows for CPUs other than ARM926T to be used for Davinci
derivative SoCs.  Existing devices (DA8x and DMx) operate unchanged.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>