[TOSA] Change to use new style of dyn_cast
LGTM. Working on merging now.
change old stype of x.dyn_cast<T>() to new style: dyn_cast<T>(x)


Signed-off-by: Tai Ly <tai.ly@arm.com>
Change-Id: I0caf0492cc21c4b6a0e679202197e212cf01740d