tree/: Make probe_opcode() flashctx argument const

Probing an opcode generally shouldn't involve mutating the flashctx
state and currently no probe_opcode functions do that.

Make the flashctx arg const so that call sites don't need to have a
non-const pointer.

Tested: ninja test

Change-Id: I19e98be50d682de2d2715417f8b7b8c62b871617
Signed-off-by: Nikolai Artemiev <nartemiev@google.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/70030
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72543
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/include/programmer.h b/include/programmer.h
index b2c47a5..2a4a8f4 100644
--- a/include/programmer.h
+++ b/include/programmer.h
@@ -307,7 +307,7 @@
 	int (*write_256)(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
 	int (*write_aai)(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
 	int (*shutdown)(void *data);
-	bool (*probe_opcode)(struct flashctx *flash, uint8_t opcode);
+	bool (*probe_opcode)(const struct flashctx *flash, uint8_t opcode);
 	void *data;
 };
 
@@ -317,7 +317,7 @@
 int default_spi_read(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int default_spi_write_256(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
 int default_spi_write_aai(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len);
-bool default_spi_probe_opcode(struct flashctx *flash, uint8_t opcode);
+bool default_spi_probe_opcode(const struct flashctx *flash, uint8_t opcode);
 int register_spi_master(const struct spi_master *mst, void *data);
 
 /* The following enum is needed by ich_descriptor_tool and ich* code as well as in chipset_enable.c. */