media: imx258: remove test pattern map from driver

change bayer order when using test pattern mode.
remove test pattern mapping method

[Sakari Ailus: Drop extra added newline]

Signed-off-by: Chen, JasonX Z <jasonx.z.chen@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>