spi-nor: Remove spi_nor::read_id operation

There is currently no useful way to override the default
implementation of this operation.  The returned struct spi_device_id
must have a pointer to struct flash_info in its private data, but this
structure is defined inside spi-nor.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index c51ee52..a98c134 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -904,8 +904,6 @@
 		return -EINVAL;
 	}
 
-	if (!nor->read_id)
-		nor->read_id = spi_nor_read_id;
 	if (!nor->wait_till_ready)
 		nor->wait_till_ready = spi_nor_wait_till_ready;
 
@@ -935,7 +933,7 @@
 	if (info->jedec_id) {
 		const struct spi_device_id *jid;
 
-		jid = nor->read_id(nor);
+		jid = spi_nor_read_id(nor);
 		if (IS_ERR(jid)) {
 			return PTR_ERR(jid);
 		} else if (jid != id) {