MIPS: ralink: fix spis group pinmux

pwm function for spis conflicts with uart2 and uart1, fix this by changing it
to pwm_uart2, which reflects the real use of these pins with these pinmux
(2 for pwm and 2 for uart).
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Cc: john@phrozen.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13369/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ralink/mt7620.c

@@ -175,7 +175,7 @@ static struct rt2880_pmx_func spi_cs1_grp_mt7628[] = {
 };
 
 static struct rt2880_pmx_func spis_grp_mt7628[] = {
-	FUNC("pwm", 3, 14, 4),
+	FUNC("pwm_uart2", 3, 14, 4),
 	FUNC("util", 2, 14, 4),
 	FUNC("gpio", 1, 14, 4),
 	FUNC("spis", 0, 14, 4),