media: ti-vpe: cal: Fix compilation on 32-bit ARM

When compiled on 32-bit ARM, the CAL driver fails with the FIELD_PREP()
macro complaining that the mask is not constant. While all callers of
the inline cal_write_field() function pass a constant mask, the mask
parameter itself is a variable, which likely doesn't please the
compiler.

Fix it by replacing FIELD_PREP() with a manual implementation.

Fixes: 50797fb3 ("media: ti-vpe: cal: Turn reg_(read|write)_field() into inline functions")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reported-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>