Revert "csitool: enable 5 GHz operation for experiments"

This reverts commits a74e0563aa2a7f61b668daf80f1148f0fc967b04 and
294a30c83358a955c40d7d7f0fc5927fe90de1c1. The regulatory settings
read from the EEPROM are used not just by the driver, but also by
the firmware. While the driver may be able to work differently by
ignoring the EEPROM settings, this approach is not ideal, because
it makes it less transparent to the user what is happening when an
operation such as IBSS beaconing is blocked outside of the driver.
Revert extra modifications to source tree

This reverts modifications to the Linux kernel stable source tree
(git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git)
except those which implement CSI Tool support. The CSI Tool README
is renamed to avoid conflicting with the Linux kernel release notes
(but it will still appear as the markdown in Github).

This makes it easier to merge this tree with distribution-specific
kernel changes, or to rebase the CSI Tool support onto other kernel
versions.
csitool: Use connector ID from out-of-tree range

This allows the iwlwifi module to be rebuilt for an existing kernel
and installed in the module 'updates' directory, without needing to
rebuild and install the entire kernel.
csitool: End error message with newline