media: ti-vpe: cal: Rename MAX_(WIDTH|HEIGHT)_* macros with CAL_ prefix
The MAX_WIDTH_BYTES and MAX_HEIGHT_LINES macros have a generic name that
is prone to namespace clashes. Rename them with a CAL_ prefix. While at
it, expand their documentation and add CAL_MIN_(WIDTH|HEIGHT)_* macros
that will be used to implement CAMERARX subdev operations.