media: atomisp: get rid of some cleanup leftovers

The code that used to check for ISP2400/2401 version were
using the revision number in order to decide wheather
version should be used. With the new version, the code
doesn't need to check anymore for ISP version.

Fixes: ca133c39 ("media: atomisp: improve device detection code")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/atomisp/pci/atomisp_v4l2.c

@@ -1429,7 +1429,6 @@ atomisp_load_firmware(struct atomisp_device *isp)
  */
 static bool is_valid_device(struct pci_dev *pdev, const struct pci_device_id *id)
 {
-	unsigned int a0_max_id = 0;
 	const char *name;
 	const char *product;
 
@@ -1437,11 +1436,9 @@ static bool is_valid_device(struct pci_dev *pdev, const struct pci_device_id *id
 
 	switch (id->device & ATOMISP_PCI_DEVICE_SOC_MASK) {
 	case ATOMISP_PCI_DEVICE_SOC_MRFLD:
-		a0_max_id = ATOMISP_PCI_REV_MRFLD_A0_MAX;
 		name = "Merrifield";
 		break;
 	case ATOMISP_PCI_DEVICE_SOC_BYT:
-		a0_max_id = ATOMISP_PCI_REV_BYT_A0_MAX;
 		name = "Baytrail";
 		break;
 	case ATOMISP_PCI_DEVICE_SOC_ANN: