pflash_cfi01: Suppress warning when Linux probes for AMD flash

There are several ARM and MIPS boards which are manufactured with
either Intel (pflash_cfi01.c) or AMD (pflash_cfi02.c) flash memory.

The Linux kernel supports both and first probes for AMD flash which
resulted in one or two warnings from the Intel flash emulation:

pflash_write: Unimplemented flash cmd sequence (offset 0000000000000000, wcycle 0x0 cmd 0x0 value 0xf000f0)
pflash_write: Unimplemented flash cmd sequence (offset 0000000000000000, wcycle 0x0 cmd 0x0 value 0xf0)

These warnings confuse users, so suppress them.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

hw/pflash_cfi01.c

@@ -319,6 +319,9 @@ static void pflash_write(pflash_t *pfl, hwaddr offset,
             DPRINTF("%s: Write to buffer\n", __func__);
             pfl->status |= 0x80; /* Ready! */
             break;
+        case 0xf0: /* Probe for AMD flash */
+            DPRINTF("%s: Probe for AMD flash\n", __func__);
+            goto reset_flash;
         case 0xff: /* Read array mode */
             DPRINTF("%s: Read array mode\n", __func__);
             goto reset_flash;