[HIP] Fix device malloc/free

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.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D116967