soc/amd/cezanne/early_fch: Perform early SPI initialization

Add the fch_spi_early_init call in fch_pre_init to perform early SPI
initialization which enables SPI ROM and setting the speed & read modes.

BUG=b:194919326
TEST=Build and boot to OS in Guybrush.

Change-Id: Ibfbe6e16bd6b0dd46c13cecf2a35f0c0b4576b88
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56684
Reviewed-by: Martin Roth <martinroth@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/cezanne/early_fch.c

@@ -44,7 +44,7 @@ void configure_port80_routing_early(void)
 void fch_pre_init(void)
 {
 	lpc_early_init();
-
+	fch_spi_early_init();
 	enable_acpimmio_decode_pm04();
 	fch_smbus_init();
 	fch_enable_cf9_io();