dfu: sf: add partition support for nor backend

Copy the partition support from NAND backend to SF,
support part and partubi option.
In case of ubi partition, erase the rest of the
partition as it is mandatory for UBI.

The added code is under compilation flag CONFIG_DFU_SF_PART
activated by default.

for example:

U-Boot> env set dfu_alt_info "spl part 0 1;\
u-boot part 0 2;u-boot-env part 0 3;UBI partubi 0 4"
U-Boot> dfu 0 sf 0:0:10000000:0

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/include/dfu.h b/include/dfu.h
index 145a157..bf51ab7 100644
--- a/include/dfu.h
+++ b/include/dfu.h
@@ -77,6 +77,8 @@
 	/* RAW programming */
 	u64 start;
 	u64 size;
+	/* for sf/ubi use */
+	unsigned int ubi;
 };
 
 #define DFU_NAME_SIZE			32