net: macb: Fix check for little-endian system in gmac_configure_dma()

Instead of depending on CONFIG_SYS_LITTLE_ENDIAN, we check at runtime
whether underlying system is little-endian or big-endian. This way
we are not dependent on any U-Boot specific OR compiler specific macro
to check system endianness.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/macb.c

@@ -91,6 +91,8 @@ struct macb_dma_desc {
 struct macb_device {
 	void			*regs;
 
+	bool			is_big_endian;
+
 	const struct macb_config *config;
 
 	unsigned int		rx_tail;
@@ -754,11 +756,10 @@ static void gmac_configure_dma(struct macb_device *macb)
 	dmacfg |= GEM_BIT(TXPBMS) | GEM_BF(RXBMS, -1L);
 	dmacfg &= ~GEM_BIT(ENDIA_PKT);
 
-#ifdef CONFIG_SYS_LITTLE_ENDIAN
-		dmacfg &= ~GEM_BIT(ENDIA_DESC);
-#else
+	if (macb->is_big_endian)
 		dmacfg |= GEM_BIT(ENDIA_DESC); /* CPU in big endian */
-#endif
+	else
+		dmacfg &= ~GEM_BIT(ENDIA_DESC);
 
 	dmacfg &= ~GEM_BIT(ADDR64);
 	gem_writel(macb, DMACFG, dmacfg);
@@ -1239,6 +1240,8 @@ static int macb_eth_probe(struct udevice *dev)
 
 	macb->regs = (void *)pdata->iobase;
 
+	macb->is_big_endian = (cpu_to_be32(0x12345678) == 0x12345678);
+
 	macb->config = (struct macb_config *)dev_get_driver_data(dev);
 	if (!macb->config)
 		macb->config = &default_gem_config;