Comment out option GPT until the matching userland bits are in place.
Rename various configuration handling functions.

Requested by and discussed with tedu@.
Move the client code into a separate file.
boot(9): Cosmetic changes to improve diff'ability.
Do not fold multiple function arguments into the same .Fn argument:
That may cause indexing and formatting issues.
Buggy mdoc(7) code mentioned by uebayasi@ to jmc@.
Split the context allocation out from the configuration. This will allow
us to properly report errors that occur during configuration processing.

Discussed with tedu@
Some reallocarray() use; review Jean-Philippe Ouellet, patrick keshishian
ok tedu
one .Fn argument per function argument
Rename the context allocation from ressl_new to ressl_client, which makes
it completely obvious what the context is for. Ensure client functions are
used on client contexts.
use mallocarray
Tabs, not spaces.
pciide.c, pciide_rdc_reg.h(new): ported rdcide(4) from NetBSD.
it supports RDC's R1012 IDE controller.

tested on 86duino EduCake (DM&P Vortex86EX SoC)

ok by deraadt@
use mallocarray()
add missing whitespace between .Fa macro argument and trailing punctuation