config/arm: reformat and move config and comments

config/arm: reformat and move config and comments

Change formatting so that it's more consistent and readable, add/modify
comments/stdout messages, move configuration options to more appropriate
places and make the order consistent according to these rules:
1. First list generic configuration options, then list options that may
   be overwritten. List SoC-specific options last.
2. For SoC-specific options, list number of cores before the number of
   NUMA nodes, to make it consistent with config/meson.build.

Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
Tested-by: Jerin Jacob <jerinj@marvell.com>
Tested-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
Tested-by: Vimal Chungath <vcchunga@amazon.com>
Tested-by: Dharmik Thakkar <dharmik.thakkar@arm.com>