Kernel/Storage: Remove InterfaceType enum

This enum was created to help put distinction between the commandset and
the interface type, as ATAPI devices are simply ATA devices utilizing
the SCSI commandset. Because we don't support ATAPI, putting such type
of distinction is pointless, so let's remove this for now.

Kernel/Storage/NVMe/NVMeNameSpace.h

@@ -33,7 +33,6 @@ public:
 private:
     NVMeNameSpace(LUNAddress, NonnullRefPtrVector<NVMeQueue> queues, size_t storage_size, size_t lba_size, size_t major_number, size_t minor_number, u16 nsid, NonnullOwnPtr<KString> early_device_name);
 
-    virtual InterfaceType interface_type() const override { return InterfaceType::NVMe; }
     u16 m_nsid;
     NonnullRefPtrVector<NVMeQueue> m_queues;
 };