soc/amd/common/block/psp/psp_smm: use raw MSR data

Since mst_t is a union of the struct containing the lower and higher 32
bits and the raw 64 bit value, there's no need to convert the lower and
higher 32 bits into a 64 bit value and we can just use the 64 bit raw
value.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I5923df84f0eb3a28ba6eda4a06c7421f4459e560
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73638
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/soc/amd/common/block/psp/psp_smm.c

@@ -51,10 +51,10 @@ int psp_notify_smm(void)
 	};
 
 	msr = rdmsr(SMM_ADDR_MSR);
-	buffer.req.smm_base = ((uint64_t)msr.hi << 32) | msr.lo;
+	buffer.req.smm_base = msr.raw;
 	msr = rdmsr(SMM_MASK_MSR);
 	msr.lo &= 0xffff0000; /* mask SMM_TSEG_VALID and reserved bits */
-	buffer.req.smm_mask = ((uint64_t)msr.hi << 32) | msr.lo;
+	buffer.req.smm_mask = msr.raw;
 
 	soc_fill_smm_trig_info(&buffer.req.smm_trig_info);
 #if (CONFIG(SOC_AMD_COMMON_BLOCK_PSP_GEN2))