spi/spi-fsl-spi: Add support for gpio chipselects for GRLIB type cores

This relies upon of_spi_register_master to find out which gpios to use.

Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/spi/spi-fsl-lib.h b/drivers/spi/spi-fsl-lib.h
index d5c788b..52db693 100644
--- a/drivers/spi/spi-fsl-lib.h
+++ b/drivers/spi/spi-fsl-lib.h
@@ -71,6 +71,7 @@
 
 #ifdef CONFIG_SPI_FSL_SPI
 	int type;
+	int native_chipselects;
 	u8 max_bits_per_word;
 
 	void (*set_shifts)(u32 *rx_shift, u32 *tx_shift,