SPI: Add vendor Atmel

Change-Id: I60e578003b857f5dcabb2e9bc75aa46acddb62b8
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7433
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Tested-by: build bot (Jenkins)

src/drivers/spi/spi_flash.c

@@ -218,6 +218,9 @@ static struct {
 #if CONFIG_SPI_FLASH_AMIC
 	{ 0, 0x37, spi_flash_probe_amic, },
 #endif
+#if CONFIG_SPI_FLASH_ATMEL
+	{ 0, 0x1f, spi_flash_probe_atmel, },
+#endif
 #if CONFIG_SPI_FLASH_EON
 	{ 0, 0x1c, spi_flash_probe_eon, },
 #endif