phy: Revert "phy: ralink: Kconfig: convert mt7621-pci-phy into 'bool'"

This reverts commit 6eded551 ("phy: ralink: Kconfig: convert
mt7621-pci-phy into 'bool'") as we don't want drivers to be built in and
should be a module instead
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/ralink/Kconfig

@@ -3,8 +3,8 @@
 # PHY drivers for Ralink platforms.
 #
 config PHY_MT7621_PCI
-	bool "MediaTek MT7621 PCI PHY Driver"
-	depends on (RALINK && OF && PCI_MT7621) || COMPILE_TEST
+	tristate "MediaTek MT7621 PCI PHY Driver"
+	depends on (RALINK && OF) || COMPILE_TEST
 	select GENERIC_PHY
 	select REGMAP_MMIO
 	help