vc/amd/fsp/morgana/FspmUpd: don't use pointers for usb_phy config

The size of a pointer changes between a 32 and 64 bit coreboot build. In
order to be able to use a 32 bit FSP in a 64 bit coreboot build, change
the pointer in the UPDs to a uint32_t to always have a 32 bit field in
the UPD for this. Also make sure that the address of the lcl_usb_phy
struct is located below the 4GB boundary, so that the truncation to 32
bits won't result in pointing to a different memory location than
intended. In this error case, which I don't expect to happen, print an
error and write 0 to mcfg->usb_phy_ptr so that the FSP will use its
default values.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I1394aa6ef5f401e0c7bdd4861f1e28ae46e56e4f
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70505
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/vendorcode/amd/fsp/morgana/FspmUpd.h

@@ -96,7 +96,8 @@ typedef struct __packed {
 	/** Offset 0x04CF**/	uint32_t                    telemetry_vddcrsocfull_scale_current;
 	/** Offset 0x04D3**/	uint32_t                    telemetry_vddcrsocOffset;
 	/** Offset 0x04D7**/	uint8_t                     UnusedUpdSpace1;
-	/** Offset 0x04D8**/	struct usb_phy_config       *usb_phy;
+	/* usb_phy_ptr is actually struct usb_phy_config *, but that won't work for 64bit coreboot */
+	/** Offset 0x04D8**/	uint32_t                    usb_phy_ptr;
 	/** Offset 0x04DC**/	uint8_t                     UnusedUpdSpace2[292];
 	/** Offset 0x0600**/	uint16_t                    UpdTerminator;
 } FSP_M_CONFIG;