ARM: DRA7: Enable software leveling for dra7

Currently hw leveling is enabled by default on DRA7/72.
But the hardware team suggested to use sw leveling as hw leveling
is not characterized and seen some test case failures.
So enabling sw leveling on all DRA7 platforms.

Signed-off-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>