ACPI: proc: Remove unused header

With `make W=1` build we get a warning:

drivers/acpi/proc.c: warning: EXPORT_SYMBOL() is not used, but #include <linux/export.h> is present

Fix it by removing unused inclusion.

Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/acpi/proc.c

···
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
-#include <linux/export.h>
 #include <linux/suspend.h>
 #include <linux/bcd.h>
 #include <linux/acpi.h>