hv: pSRAM: add PTCT parsing code

The added parse_ptct function will parse native ACPI PTCT table to
acquire information like pSRAM location/size/level and PTCM location,
and save them.

Tracked-On: #5330
Signed-off-by: Qian Wang <qian1.wang@intel.com>

hypervisor/boot/include/acpi.h

@@ -57,6 +57,7 @@
 #define ACPI_SIG_MCFG            "MCFG" /* Memory Mapped Configuration table */
 #define ACPI_SIG_DSDT            "DSDT" /* Differentiated System Description Table */
 #define ACPI_SIG_TPM2            "TPM2" /* Trusted Platform Module hardware interface table */
+#define ACPI_SIG_PTCT            "PTCT" /* Platform Tuning Configuration Table (Real-Time Configuration Table) */
 
 struct packed_gas {
 	uint8_t 	space_id;