mtd: cfi_cmdset_0002: make sector erase command variable

Some old SST chips use 0x50 as sector erase command, instead
of 0x30. Make this value variable to handle such chips.

Signed-off-by: Guillaume LECERF <glecerf@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/chips/cfi_probe.c b/drivers/mtd/chips/cfi_probe.c
index 8f5b96a..d255352 100644
--- a/drivers/mtd/chips/cfi_probe.c
+++ b/drivers/mtd/chips/cfi_probe.c
@@ -177,6 +177,8 @@
 
 	cfi->cfi_mode = CFI_MODE_CFI;
 
+	cfi->sector_erase_cmd = CMD(0x30);
+
 	/* Read the CFI info structure */
 	xip_disable_qry(base, map, cfi);
 	for (i=0; i<(sizeof(struct cfi_ident) + num_erase_regions * 4); i++)