ppc/ppc405: Remove flash support

It is currently impossible to find a "ppc405_rom.bin" firmware file or
a full flash image for the PPC405EP evalution board. Even if it should
be technically possible to recreate such an image, it's unlikely that
anyone will do it since the board is obsolete and support in QEMU has
been broken for about 10 years.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20211206103712.1866296-9-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/ppc/ppc405_boards.c

@@ -161,7 +161,6 @@ static void ref405ep_init(MachineState *machine)
     long kernel_size, initrd_size;
     int linux_boot;
     int len;
-    DriveInfo *dinfo;
     MemoryRegion *sysmem = get_system_memory();
     DeviceState *uicdev;
 
@@ -189,19 +188,8 @@ static void ref405ep_init(MachineState *machine)
     memory_region_init_ram(sram, NULL, "ef405ep.sram", PPC405EP_SRAM_SIZE,
                            &error_fatal);
     memory_region_add_subregion(sysmem, PPC405EP_SRAM_BASE, sram);
+
     /* allocate and load BIOS */
-#ifdef USE_FLASH_BIOS
-    dinfo = drive_get(IF_PFLASH, 0, 0);
-    if (dinfo) {
-        bios_size = 8 * MiB;
-        pflash_cfi02_register((uint32_t)(-bios_size),
-                              "ef405ep.bios", bios_size,
-                              blk_by_legacy_dinfo(dinfo),
-                              64 * KiB, 1,
-                              2, 0x0001, 0x22DA, 0x0000, 0x0000, 0x555, 0x2AA,
-                              1);
-    } else
-#endif
     {
         bios = g_new(MemoryRegion, 1);
         memory_region_init_rom(bios, NULL, "ef405ep.bios", BIOS_SIZE,