intel/broadwell: bootstate mechanism only exists in ramstage

So don't try to use it elsewhere.

Change-Id: Ia600ba654bde36d3ea8a0f3185afae00fe50bfe9
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10030
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/broadwell/spi.c

@@ -312,12 +312,14 @@ void spi_init(void)
 	pci_write_config_byte(dev, 0xdc, bios_cntl | 0x1);
 }
 
+#if ENV_RAMSTAGE
 static void spi_init_cb(void *unused)
 {
 	spi_init();
 }
 
 BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_ENTRY, spi_init_cb, NULL);
+#endif
 
 int spi_claim_bus(struct spi_slave *slave)
 {