xtensa: configs: Cleanup old Kconfig IO scheduler options

CONFIG_IOSCHED_DEADLINE and CONFIG_IOSCHED_CFQ are gone since
commit f382fb0b ("block: remove legacy IO schedulers").

The IOSCHED_DEADLINE was replaced by MQ_IOSCHED_DEADLINE and it will be
now enabled by default (along with MQ_IOSCHED_KYBER).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Message-Id: <20200130192129.2677-1-krzk@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>