misc: pmem_wrapper: Do not allow custom ion client name. Rename heap_mask.

Using the ion client name as pmem client name makes much more sense.
Rename heap_mask to ion_heap_mask so it would be clearer.

Change-Id: I9d2fd9d6674c208e3f0e3200a64fc50b469d574e
u8800: Do not set custom ion client name. Update heap_mask.

Change-Id: I33304f0fda9daa1fd87d94272785366ccb4146bf