printk: Remove redundant CONFIG_BASE_FULL

CONFIG_BASE_FULL is equivalent to !CONFIG_BASE_SMALL and is enabled by
default: CONFIG_BASE_SMALL is the special case to take care of.
So, remove CONFIG_BASE_FULL and move the config choice to
CONFIG_BASE_SMALL (which defaults to 'n')

For defconfigs explicitely disabling BASE_FULL, explicitely enable
BASE_SMALL.
For defconfigs explicitely enabling BASE_FULL, drop it as it is the
default.

Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240505080343.1471198-4-yoann.congal@smile.fr
Signed-off-by: Petr Mladek <pmladek@suse.com>