libpayload: Parse the ACPI RSDP table entry

Change-Id: I583cda63c3f0b58f8d198ed5ecea7c4619c7a897
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62576
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

payloads/libpayload/include/sysinfo.h

@@ -111,6 +111,7 @@ struct sysinfo_t {
 	uintptr_t mrc_cache;
 	uintptr_t acpi_gnvs;
 	uintptr_t acpi_cnvs;
+	uintptr_t acpi_rsdp;
 
 #define UNDEFINED_STRAPPING_ID	(~0)
 #define UNDEFINED_FW_CONFIG	~((uint64_t)0)