spi: Use bus probing for SFDP

Only probe for the SFDP signature and split the actual SFDP parsing
into a chip preparation function.

Change-Id: I182d0a386bb2fd11951a1c9f2f965ce68ff57cf0
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/427
diff --git a/include/chipdrivers/spi.h b/include/chipdrivers/spi.h
index b664a19..547885c 100644
--- a/include/chipdrivers/spi.h
+++ b/include/chipdrivers/spi.h
@@ -130,6 +130,7 @@
 void decode_range_spi25_2x_block(size_t *start, size_t *len, const struct wp_bits *, size_t chip_len);
 
 /* sfdp.c */
-int probe_spi_sfdp(struct flashprog_flashctx *);
+struct found_id *probe_spi_sfdp(const struct bus_probe *, const struct master_common *);
+int spi_prepare_sfdp(struct flashprog_flashctx *, enum preparation_steps);
 
 #endif /* !__CHIPDRIVERS_SPI_H__ */