ACPICA: Add start method for ARM FF-A

Add TPM start method for ARM FF-A defined in the TCG ACPI specification
v1.4.

See: https://trustedcomputinggroup.org/wp-content/uploads/TCG-ACPI-Specification-Version-1.4-Revision-15_pub.pdf

[jarkko:
 1. Fine-tuned the commit message.
 2. Added link to the TCG ACPI specification.]

Link: acpica/acpica#1000
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stuart Yoder <stuart.yoder@arm.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

Author: stuyod01

include/acpi/actbl3.h

@@ -466,6 +466,7 @@ struct acpi_tpm2_phy {
 #define ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC       11	/* V1.2 Rev 8 */
 #define ACPI_TPM2_RESERVED                          12
 #define ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON        13
+#define ACPI_TPM2_CRB_WITH_ARM_FFA                  15
 
 /* Optional trailer appears after any start_method subtables */