spl: replace CONFIG_SPL_SPI_* with CONFIG_SF_DEFAULT_*

Currently, CONFIG_SPL_SPI_* #defines are used for controlling SPI boot in
SPL. These #defines do not allow the user to select SPI mode for the SPI flash
(there's no CONFIG_SPL_SPI_MODE, so the SPI mode is hardcoded in
spi_spl_load.c), and duplicate information already provided by
CONFIG_SF_DEFAULT_* #defines.

Kill CONFIG_SPL_SPI_*, and use CONFIG_SF_DEFAULT_* instead.

Cc: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: Vitaly Andrianov <vitalya@ti.com>
Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Bo Shen <voice.shen@atmel.com>
Cc: Hannes Petermaier <hannes.petermaier@br-automation.com>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
diff --git a/include/spi_flash.h b/include/spi_flash.h
index 2db53c7..408a5b4 100644
--- a/include/spi_flash.h
+++ b/include/spi_flash.h
@@ -19,6 +19,19 @@
 #include <linux/types.h>
 #include <linux/compiler.h>
 
+#ifndef CONFIG_SF_DEFAULT_SPEED
+# define CONFIG_SF_DEFAULT_SPEED	1000000
+#endif
+#ifndef CONFIG_SF_DEFAULT_MODE
+# define CONFIG_SF_DEFAULT_MODE		SPI_MODE_3
+#endif
+#ifndef CONFIG_SF_DEFAULT_CS
+# define CONFIG_SF_DEFAULT_CS		0
+#endif
+#ifndef CONFIG_SF_DEFAULT_BUS
+# define CONFIG_SF_DEFAULT_BUS		0
+#endif
+
 /* sf param flags */
 #define SECT_4K		1 << 1
 #define SECT_32K	1 << 2