media: ccs: Remove unused declarations

Commit 2989a457 ("media: ccs: Refactor register reading a little")
removed ccs_read_addr_no_quirk() but left declaration.

Commit 52932211 ("media: ccs: Use V4L2 CCI for accessing sensor
registers") removed ccs_write_addr_no_quirk() and ccs_reg_width() but
leave their declarations.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>