Documentation: admin-guide: correct spelling

Correct spelling problems for Documentation/admin-guide/ as reported
by codespell.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: dm-devel@redhat.com
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230129231053.20863-2-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide: media/building: drop doubled words

Drop some doubled words.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Link: https://lore.kernel.org/r/20200704032020.21923-5-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

media: admin-guide: add a generic building guide

Several of the existing documents under the media admin-guide
contain build procedures.

Add an specific chapter describing it. This document was
partially inspired on the modifications I made to the bttv.rst
file.

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