ARC: [plat-axs103] Add temporary quirk to reset ethernet IP

DW ethernet controller on AXS10x hangs sometimes after SW reset, so
add temporary quirk to reset DW ethernet controller IP core.
This quirk can be removed after axs10x reset driver
(see http://patchwork.ozlabs.org/patch/800273/)
or simple reset driver
(see https://patchwork.kernel.org/patch/9903375/)
will be available in upstream.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/plat-axs10x/axs10x.c

@@ -111,6 +111,13 @@ static void __init axs10x_early_init(void)
 
 	axs10x_enable_gpio_intc_wire();
 
+	/*
+	 * Reset ethernet IP core.
+	 * TODO: get rid of this quirk after axs10x reset driver (or simple
+	 * reset driver) will be available in upstream.
+	 */
+	iowrite32((1 << 5), (void __iomem *) CREG_MB_SW_RESET);
+
 	scnprintf(mb, 32, "MainBoard v%d", mb_rev);
 	axs10x_print_board_ver(CREG_MB_VER, mb);
 }