Documentation/admin-guide: kernel-parameters: update CMA entries

Add qualifying build option legend [CMA] to kernel boot options
that requirce CMA support to be enabled for them to be usable.

Also capitalize 'CMA' when it is used as an acronym.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Link: https://lore.kernel.org/r/20210125043202.22399-1-rdunlap@infradead.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>