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/lib/Makefile b/arch/x86/lib/Makefile
index ba07ac7..1e8efcc 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -33,6 +33,7 @@
 obj-y	+= sections.o
 obj-y += sfi.o
 obj-y	+= string.o
+obj-y	+= acpi.o
 obj-$(CONFIG_HAVE_ACPI_RESUME) += acpi_s3.o
 ifndef CONFIG_QEMU
 obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi_table.o