soc/amd/phoenix/root_complex: make read_fsp_resources call conditional

Only call read_fsp_resources if PLATFORM_USES_FSP2_0 is selected in
Kconfig.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ic63e0904ad04dbecfac1be4d59abbb8d4f9f11d0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80271
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/soc/amd/phoenix/root_complex.c

@@ -150,6 +150,7 @@ void read_soc_memmap_resources(struct device *dev, unsigned long *idx)
 	/* Reserve fixed IOMMU MMIO region */
 	mmio_range(dev, (*idx)++, IOMMU_RESERVED_MMIO_BASE, IOMMU_RESERVED_MMIO_SIZE);
 
+	if (CONFIG(PLATFORM_USES_FSP2_0))
 		read_fsp_resources(dev, idx);
 }