spi: gpio: Drop unused spi_to_pdata()

Spi_to_pdata() is not used anywhere in the code. Drop it.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-gpio.c

@@ -96,12 +96,6 @@ spi_to_spi_gpio(const struct spi_device *spi)
 	return spi_gpio;
 }
 
-static inline struct spi_gpio_platform_data *__pure
-spi_to_pdata(const struct spi_device *spi)
-{
-	return &spi_to_spi_gpio(spi)->pdata;
-}
-
 /* These helpers are in turn called by the bitbang inlines */
 static inline void setsck(const struct spi_device *spi, int is_on)
 {