media: platform: ao-cec-g12a: remove spin_lock_irqsave() locking in meson_ao_cec_g12a_read/write

Since locking is handled by regmap, the spin_lock_irqsave() in the
meson_ao_cec_g12a_read/write() regmap callbacks is not needed.

Fixes: b7778c46 ("media: platform: meson: Add Amlogic Meson G12A AO CEC Controller driver")

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>