media: atomisp: get rid of some cleanup leftovers

The code that used to check for ISP2400/2401 version were
using the revision number in order to decide wheather
version should be used. With the new version, the code
doesn't need to check anymore for ISP version.

Fixes: ca133c39 ("media: atomisp: improve device detection code")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>