sata_sil: Fix build breakage

Commit e57db7bd (SATA Sil: Blacklist system that spins off disks during ACPI power off)
 breaks build like the following, in both cases when CONFIG_DMI set or not.

        drivers/ata/sata_sil.c: In function 'sil_broken_system_poweroff':
        drivers/ata/sata_sil.c:713: error: implicit declaration of function 'dmi_first_match'
        drivers/ata/sata_sil.c:713: warning: initialization makes pointer from integer without a cast

  sata_sil.c should include dmi.h
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/ata/sata_sil.c

@@ -44,6 +44,7 @@
 #include <linux/device.h>
 #include <scsi/scsi_host.h>
 #include <linux/libata.h>
+#include <linux/dmi.h>
 
 #define DRV_NAME	"sata_sil"
 #define DRV_VERSION	"2.4"