media: atomisp: pci: release_version is now irci_stable_candrpv_0415_20150521_0458

Now that we made atomisp work with firmware version
irci_stable_candrpv_0415_20150521_0458 also for ISP2401, the
release_version for ISP2401 is not irci_ecr-master_20150911_0724
anymore.

So, use the same release_version for both ISP2400 and ISP2401 (i.e.,
irci_stable_candrpv_0415_20150521_0458).

Referred to the following diff to make this patch:
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/diff/drivers/staging/media/atomisp/pci/sh_css_firmware.c?id=3c0538fbad9f1d07d588f631e380256d941e3d3a
("media: atomisp: get rid of most checks for ISP2401 version")
changes for file sh_css_firmware.c

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>