This function will be needed by the upcoming Designware master SPI driver. Signed-off-by: Stefan Roese <sr@denx.de> Cc: Chin Liang See <clsee@altera.com> Cc: Dinh Nguyen <dinguyen@altera.com> Cc: Vince Bridgers <vbridger@altera.com> Cc: Marek Vasut <marex@denx.de> Cc: Pavel Machek <pavel@denx.de>