soc/intel/denverton_ns: Fix MRC_RW_CACHE

It is required to set WPD (Write Protect Disable) bit
to make it possible to use MRC_RW_CACHE region with
CACHE_MRC_SETTINGS=y.

Change-Id: Iacab44b00d08c9bdc18bc3bdcb88833634c0b02e
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60091
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/intel/denverton_ns/bootblock/bootblock.c

@@ -84,6 +84,7 @@ void bootblock_soc_early_init(void)
 #if (CONFIG(CONSOLE_SERIAL))
 	early_uart_init();
 #endif
+	fast_spi_early_init(DEFAULT_SPI_BASE);
 };
 
 void bootblock_soc_init(void)