libata: fix suspend/resume for ATA SEMB devices

79b42bab fixed identifying ATA devices
reporting 3c/c3 signature which belongs to SEMB devices now. However,
suspending the machine with such device (WDC WD2500AAJS-6 01.0) fails
with the following:

hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4
hda: UDMA/100 mode selected
hdb: host max PIO4 wanted PIO255(auto-tune) selected PIO4
hdb: UDMA/66 mode selected
sd 1:0:0:0: [sda] Starting disk
ata5: SATA link down (SStatus 0 SControl 300)
ata1: SATA link down (SStatus 0 SControl 300)
ata3: SATA link down (SStatus 0 SControl 300)
ata6: SATA link down (SStatus 0 SControl 300)
ata2: softreset failed (device not ready)
ata2: failed due to HW bug, retry pmp=0
ata4: softreset failed (device not ready)
ata4: failed due to HW bug, retry pmp=0
ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.00: class mismatch 1 != 7
ata2.00: revalidation failed (errno=-19)
ata2: limiting SATA link speed to 1.5 Gbps
ata4.00: configured for UDMA/133
ata2: softreset failed (device not ready)
ata2: failed due to HW bug, retry pmp=0
ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
ata2.00: class mismatch 1 != 7
ata2.00: revalidation failed (errno=-19)
ata2.00: disabled
sd 1:0:0:0: rejecting I/O to offline device
sd 1:0:0:0: [sda] START_STOP FAILED
sd 1:0:0:0: [sda] Result: hostbyte=0x01 driverbyte=0x00
PM: Device 1:0:0:0 failed to thaw: error 65536
sd 3:0:0:0: [sdb] Starting disk

due to a class mismatch in ata_dev_revalidate(). Fix it by adding the
ATA_DEV_SEMB device class to the check.

CC: Tejun Heo <htejun@gmail.com>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>