SPI: Fix and enable Fast Read support

- Fix handling of 5-byte Fast Read command in the ICH SPI
driver.  This fix is ported from the U-boot driver.
- Allow CONFIG_SPI_FLASH_NO_FAST_READ to be overridden by
defining a name for the bool in Kconfig and removing the
forced select in southbridge config
- Fix use of CONFIG_SPI_FLASH_NO_FAST_READ in SPI drivers
to use #if instead of #ifdef
- Relocate flash functions in SMM so they are usable.
This really only needs to happen for read function pointer
since it uses a global function rather than a static one from
the chip, but it is good to ensure the rest are set up
correctly as well.

Change-Id: Ic1bb0764cb111f96dd8a389d83b39fe8f5e72fbd
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/1775
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/drivers/spi/spi_flash.c

@@ -281,7 +281,7 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
 	/* search the table for matches in shift and id */
 	for (i = 0; i < ARRAY_SIZE(flashes); ++i)
 		if (flashes[i].shift == shift && flashes[i].idcode == *idp) {
-#ifdef __SMM__
+#if CONFIG_SMM_TSEG && defined(__SMM__)
 			/* Need to relocate this function */
 			tseg_relocate((void **)&flashes[i].probe);
 #endif
@@ -296,6 +296,14 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
 		goto err_manufacturer_probe;
 	}
 
+#if CONFIG_SMM_TSEG && defined(__SMM__)
+	/* Ensure flash handlers are valid for TSEG */
+	tseg_relocate((void **)&flash->read);
+	tseg_relocate((void **)&flash->write);
+	tseg_relocate((void **)&flash->erase);
+	tseg_relocate((void **)&flash->name);
+#endif
+
 	printk(BIOS_INFO, "SF: Detected %s with page size %x, total %x\n",
 			flash->name, flash->sector_size, flash->size);