docs: efi: add CPER functions to driver-api

docs: efi: add CPER functions to driver-api

There are two kernel-doc like descriptions at cper, which is used
by other parts of cper and on ghes driver. They both have kernel-doc
like descriptions.

Change the tags for them to be actual kernel-doc tags and add them
to the driver-api documentaion at the UEFI section.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>