ROCm 4.5 device library introduced __ockl_dm_alloc and __ockl_dm_dealloc
for supporting device side malloc/free.
This patch redefines device malloc/free to use these functions.
It also fixes a bug in the wrapper header which incorrectly defines free
with return type void* instead of void.
Nit: perhaps something like this would express the intent a bit more directly: