arm64/dts: increase Tuscany ML model heap to 60M

With the most recent pipeline_input release for Tuscany, an additional
context model was used (v2.1 for auth) but enrollment is still using
v2.0 (intentional). That pushed the pipeline_input size from 46MB to
~53MB, just over the dma_heap famodel limit of ~52MB.

Bug: 196409876
Signed-off-by: Jidong Sun <jidong@google.com>
Change-Id: I9890ab87ec7752c308a599a1fc0077c407f87d61