acpi: Add #define for Mutex "no timeout" value

Some acpigen code may use mutexes, and it is a common idiom to pass
a value for the Timeout field of 0xffff, which is interpreted by OSPM
to mean "no timeout". Therefore add a macro for this value.

BUG=b:197983574

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: I16bc9f3f04dd1e3dc0f3eca3e56377e6f48132b2
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59851
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>

src/include/acpi/acpigen.h

@@ -298,6 +298,8 @@ struct cppc_config {
 	cppc_entry_t entries[CPPC_MAX_FIELDS_VER_3];
 };
 
+#define ACPI_MUTEX_NO_TIMEOUT		0xffff
+
 void acpigen_write_return_integer(uint64_t arg);
 void acpigen_write_return_namestr(const char *arg);
 void acpigen_write_return_string(const char *arg);