staging: fbtft: Add support for orientation on Himax HX8347d

Himax HX8347d has non-standard register to control orientation.
Add support for different orientation values.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210503172114.27891-4-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>