spi: s3c64xx: Add fix for crash in spi suspend/resume

The SPI driver makes a gpio_request during initialization. The requested
gpios need to be populated as part of the s3c64xx_spi_driver_data so that
they can be released during suspend and requested again during resume.

Add the missing code to save the requested gpios as part of the driver
data. This fixes a SPI driver suspend crash.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>