ata: hpt366: fix incorrect mask when checking at cmd_high_time

According to the HPT366 data sheet, PCI config space dword 0x40-0x43
bits 11:8 specify the primary drive cmd_high_time, however,
currently just 3 bits of the 4 are being used because the mask
is 0x700 and not 0x0f00.  Fix the mask, allowing for the 40MHz clock
to be detected.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/pata_hpt366.c b/drivers/ata/pata_hpt366.c
index e5fb752..a219a50 100644
--- a/drivers/ata/pata_hpt366.c
+++ b/drivers/ata/pata_hpt366.c
@@ -368,7 +368,7 @@
 
 	/* PCI clocking determines the ATA timing values to use */
 	/* info_hpt366 is safe against re-entry so we can scribble on it */
-	switch ((reg1 & 0x700) >> 8) {
+	switch ((reg1 & 0xf00) >> 8) {
 	case 9:
 		hpriv = &hpt366_40;
 		break;