media: atomisp: remove struct ia_css_isp_parameter xnr3

This patch removes `struct ia_css_isp_parameter xnr3` from
`struct ia_css_memory_offsets` as well as its usage [1].

[1] added on updating css version to irci_master_20150701_0213
https://raw.githubusercontent.com/intel/ProductionKernelQuilts/cht-m1stable-2016_ww31/uefi/cht-m1stable/patches/cam-0439-atomisp2-css2401-and-2401_legacy-irci_master_2015070.patch
("atomisp2: css2401 and 2401_legacy-irci_master_20150701_0213")

Signed-off-by: Tsuchiya Yuto <kitakar@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: atomisp: add SPDX headers

This driver is licensed under GPL 2.0, as stated inside their
headers.

Add the proper tag there. We should probably latter cleanup
the reduntant licensing text, but this could be done later,
after we get rid of other abstraction layers.

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

media: atomisp: cleanup directory hierarchy

This driver has very long directories without a good
reason (IMHO). Let's drop two directories from such hierarchy,
in order to simplify things a little bit and make the dir
output a bit more readable.

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