mtd: spi-nor-core: Introduce flash-specific fixup hooks

Sometimes the information in a flash's SFDP tables is wrong. Sometimes
some information just can't be expressed in the SFDP table. So,
introduce the fixup hooks to allow tailoring settings for a specific
flash.

Three hooks are added: default_init, post_sfdp, and post_bfpt. These
allow tweaking the flash settings at different point in the probe
sequence. Since the hooks reside in nor->info, set that value just
before the call to spi_nor_init_params().

The hooks and at what points they are executed mimics Linux's spi-nor
framework. One major difference is that Linux puts the struct
spi_nor_fixups in nor->info. This is not possible in U-Boot because the
spi-nor-ids list is shared between spi-nor-core.c and spi-nor-tiny.c.
Since spi-nor-tiny shouldn't have those fixup hooks populated, add a
separate function that lets flashes populate their fixup hooks.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 47a2ece..b2e9e08 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -416,6 +416,7 @@
  * @write_proto:	the SPI protocol for write operations
  * @reg_proto		the SPI protocol for read_reg/write_reg/erase operations
  * @cmd_buf:		used by the write_reg
+ * @fixups:		flash-specific fixup hooks.
  * @prepare:		[OPTIONAL] do some preparations for the
  *			read/write/erase/lock/unlock operations
  * @unprepare:		[OPTIONAL] do some post work after the
@@ -457,6 +458,7 @@
 	bool			sst_write_second;
 	u32			flags;
 	u8			cmd_buf[SPI_NOR_MAX_CMD_SIZE];
+	struct spi_nor_fixups	*fixups;
 
 	int (*setup)(struct spi_nor *nor, const struct flash_info *info,
 		     const struct spi_nor_flash_parameter *params,