PCI: mt7621: Remove unused function pcie_rmw()

Function pcie_rmw() is not being used at all and can be deleted. Hence get
rid of it, which fixes this warning:

  drivers/pci/controller/pcie-mt7621.c:112:20: warning: unused function 'pcie_rmw' [-Wunused-function]

Fixes: 2bdd5238 ("PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver")
Link: https://lore.kernel.org/r/20220124113003.406224-3-sergio.paracuellos@gmail.com
Link: https://lore.kernel.org/all/202201241754.igtHzgHv-lkp@intel.com/Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/controller/pcie-mt7621.c

@@ -109,15 +109,6 @@ static inline void pcie_write(struct mt7621_pcie *pcie, u32 val, u32 reg)
 	writel_relaxed(val, pcie->base + reg);
 }
 
-static inline void pcie_rmw(struct mt7621_pcie *pcie, u32 reg, u32 clr, u32 set)
-{
-	u32 val = readl_relaxed(pcie->base + reg);
-
-	val &= ~clr;
-	val |= set;
-	writel_relaxed(val, pcie->base + reg);
-}
-
 static inline u32 pcie_port_read(struct mt7621_pcie_port *port, u32 reg)
 {
 	return readl_relaxed(port->base + reg);