net: lpc-enet: move phy setup into platform code

Setting the phy mode requires touching a platform specific
register, which prevents us from building the driver without
its header files.

Move it into a separate function in arch/arm/mach/lpc32xx
to hide the core registers from the network driver.

Link: https://lore.kernel.org/r/20190809144043.476786-8-arnd@arndb.de
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-lpc32xx/common.c

@@ -63,6 +63,18 @@ u32 lpc32xx_return_iram(void __iomem **mapbase, dma_addr_t *dmaaddr)
 }
 EXPORT_SYMBOL_GPL(lpc32xx_return_iram);
 
+void lpc32xx_set_phy_interface_mode(phy_interface_t mode)
+{
+	u32 tmp = __raw_readl(LPC32XX_CLKPWR_MACCLK_CTRL);
+	tmp &= ~LPC32XX_CLKPWR_MACCTRL_PINS_MSK;
+	if (mode == PHY_INTERFACE_MODE_MII)
+		tmp |= LPC32XX_CLKPWR_MACCTRL_USE_MII_PINS;
+	else
+		tmp |= LPC32XX_CLKPWR_MACCTRL_USE_RMII_PINS;
+	__raw_writel(tmp, LPC32XX_CLKPWR_MACCLK_CTRL);
+}
+EXPORT_SYMBOL_GPL(lpc32xx_set_phy_interface_mode);
+
 static struct map_desc lpc32xx_io_desc[] __initdata = {
 	{
 		.virtual	= (unsigned long)IO_ADDRESS(LPC32XX_AHB0_START),