phy: ralink: phy-mt7621-pci: drop 'of_match_ptr' to fix -Wunused-const-variable

The of_device_id is included unconditionally by of.h header and used
in the driver as well. Remove of_match_ptr to fix W=1 compile test
warning with !CONFIG_OF:

drivers/phy/ralink/phy-mt7621-pci.c:341:34: warning: unused variable 'mt7621_pci_phy_ids' [-Wunused-const-variable]
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20210603043219.32646-1-sergio.paracuellos@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/ralink/phy-mt7621-pci.c

@@ -341,7 +341,7 @@ static struct platform_driver mt7621_pci_phy_driver = {
 	.probe = mt7621_pci_phy_probe,
 	.driver = {
 		.name = "mt7621-pci-phy",
-		.of_match_table = of_match_ptr(mt7621_pci_phy_ids),
+		.of_match_table = mt7621_pci_phy_ids,
 	},
 };