xilinx uart fix

recipes-kernel/linux/linux-xlnx/xilinx_uartps.c.patch

+diff -Naur a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
+--- a/drivers/tty/serial/xilinx_uartps.c	2016-02-19 13:41:58.380680377 -0700
++++ b/drivers/tty/serial/xilinx_uartps.c	2016-02-19 13:47:50.776674338 -0700
+@@ -704,6 +704,9 @@
+ 	ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
+ 	cdns_uart_writel(ctrl_reg, CDNS_UART_CR_OFFSET);
+ 
++	while (cdns_uart_readl(CDNS_UART_CR_OFFSET) &
++			(CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST))
++		cpu_relax();
+ 	/*
+ 	 * Clear the RX disable and TX disable bits and then set the TX enable
+ 	 * bit and RX enable bit to enable the transmitter and receiver.

recipes-kernel/linux/linux-xlnx_4.0.bbappend

@@ -3,6 +3,7 @@ FILESEXTRAPATHS_prepend := "${THISDIR}/config:"
 
 SRC_URI_append += " file://xilinx_nandps_elphel393.patch"
 SRC_URI_append += " file://xilinx_emacps.c.patch"
+SRC_URI_append += " file://xilinx_uartps.c.patch"
 SRC_URI_append += " file://si5338_vsc330x.patch"
 SRC_URI_append += " file://drivers-elphel.patch"