arch/x86/include/smm_call: use pm_acpi_smi_cmd_port

Use pm_acpi_smi_cmd_port() to get the APMC trigger IO port instead of
using the hard-coded APM_CNT define. This makes sure that the correct
APMC IO port will be used even when a system doesn't use the default
APM IO port.

TEST=SMMSTORE V2 still works with the EDK2 payload on Careena

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Icb79c91cfcd75db760bd80cff7f3d0400d1f16cd
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79568
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/include/smm_call.h

@@ -11,13 +11,14 @@
  */
 static inline u32 call_smm(u8 cmd, u8 subcmd, void *arg)
 {
+	const uint16_t apmc_port = pm_acpi_smi_cmd_port();
 	u32 res = 0;
 	__asm__ __volatile__ (
 		"outb %%al, %%dx"
 		: "=a" (res)
 		: "a" ((subcmd << 8) | cmd),
 		  "b" (arg),
-		  "d" (APM_CNT)
+		  "d" (apmc_port)
 		: "memory");
 	return res;
 }