media: atomisp: disable the dynamic and reserved pools

The memory management code for atomisp is complex: it has 2
extra pools (plus some ION-specific code).

The code for those extra pools are complex, and there are even
some parts of code over there that were forked from some
mm/ code, probably from Kernel 3.10.

Let's just use a single one, in order to make the driver
simpler.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>