inmates: fix pci MSI-X support code bug

The "Message Control" field of a MSI-X capability structure starts two
bytes after the capabilty id, not just one.

Signed-off-by: Henning Schild <henning.schild@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
tools: config-create: rename parse_cmdline to parse_kernel_cmdline

`parse_cmdline` is quite missleading in the context of a script with
command-line parameters. Thus better name it for what it does, parse the
kernel command line.

Signed-off-by: Benjamin Block <bebl@mageta.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Documentation: Introduce coding style

As the number of external contributions to Jailhouse grows, the need
for some formal coding style to ease review process and integration
arise. This is the first attempt to summarize what's have been discussed
on jailhouse-dev@googlegroups.com mailing list so far.

Signed-off-by: Valentine Sinitsyn <valentine.sinitsyn@gmail.com>
[Jan: clarify include block separation]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>