exynos/snow: set SPI clock rate in romstage main

This moves the setting of SPI clock rate into romstage's main,
which allows us to eliminate a bunch of dependencies from the
bootblock (about 7KB worth).

Change-Id: I371499bb4af6a6aa838294bc56f9dbc21864957a
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2346
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/cpu/samsung/exynos5-common/spi.c

@@ -83,7 +83,6 @@ static void exynos_spi_rx_tx(struct exynos_spi *regs, int todo,
 
 int exynos_spi_open(struct exynos_spi *regs)
 {
-	clock_set_rate(PERIPH_ID_SPI1, 50000000); /* set spi clock to 50Mhz */
 	/* set the spi1 GPIO */
 
 	// TODO Some of these should be done in board's bootblock file.