Kconfig: Remove all default n options

default n doesn't need to be specified. It is default option anyway.
Similar changes have been done by commit 18370f14 ("Kconfig: Remove all
default n/no options").

Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>