x86: acpi: Make enter_acpi_mode() public

enter_acpi_mode() is useful on other boot path like S3 resume, so
make it public.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>

arch/x86/include/asm/acpi_table.h

@@ -316,6 +316,15 @@ int acpi_create_madt_lapic_nmi(struct acpi_madt_lapic_nmi *lapic_nmi,
 			       u8 cpu, u16 flags, u8 lint);
 u32 acpi_fill_madt(u32 current);
 void acpi_create_gnvs(struct acpi_global_nvs *gnvs);
+/**
+ * enter_acpi_mode() - enter into ACPI mode
+ *
+ * This programs the ACPI-defined PM1_CNT register to enable SCI interrupt
+ * so that the whole system swiches to ACPI mode.
+ *
+ * @pm1_cnt:	PM1_CNT register I/O address
+ */
+void enter_acpi_mode(int pm1_cnt);
 ulong write_acpi_tables(ulong start);
 
 /**

arch/x86/lib/acpi_table.c

@@ -304,7 +304,7 @@ static void acpi_create_mcfg(struct acpi_mcfg *mcfg)
 	header->checksum = table_compute_checksum((void *)mcfg, header->length);
 }
 
-static void enter_acpi_mode(int pm1_cnt)
+void enter_acpi_mode(int pm1_cnt)
 {
 	u16 val = inw(pm1_cnt);