x86: acpi: Move APIs unrelated to ACPI tables generation to a separate library

acpi_find_fadt(), acpi_find_wakeup_vector() and enter_acpi_mode()
are something unrelated to ACPI tables generation. Move these to
a separate library.

This also fixes several style issues reported by checkpatch in the
original codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
new file mode 100644
index 0000000..4475d04
--- /dev/null
+++ b/arch/x86/include/asm/acpi.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#ifndef __ASM_ACPI_H__
+#define __ASM_ACPI_H__
+
+struct acpi_fadt;
+
+/**
+ * acpi_find_fadt() - find ACPI FADT table in the system memory
+ *
+ * This routine parses the ACPI table to locate the ACPI FADT table.
+ *
+ * @return:	a pointer to the ACPI FADT table in the system memory
+ */
+struct acpi_fadt *acpi_find_fadt(void);
+
+/**
+ * acpi_find_wakeup_vector() - find OS installed wake up vector address
+ *
+ * This routine parses the ACPI table to locate the wake up vector installed
+ * by the OS previously.
+ *
+ * @fadt:	a pointer to the ACPI FADT table in the system memory
+ * @return:	wake up vector address installed by the OS
+ */
+void *acpi_find_wakeup_vector(struct acpi_fadt *fadt);
+
+/**
+ * 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);
+
+#endif /* __ASM_ACPI_H__ */