release-7: backport add SFP0..3 LED indication

@@ -93,0 +100,4 @@
+        let len: usize = pl::csr::DRTIO.len();
+        READ_RTIO_LED = 0;
+        for linkno in 0..len {
+            //let linkno = linkno as usize;

@@ -93,0 +117,4 @@
+        unsafe {
+            let i2c = (&mut i2c::I2C_BUS).as_mut().unwrap();
+            for expander_i in 0..=1 {
+                let mut io_expander = io_expander::IoExpander::new(i2c, expander_i).unwrap();

@@ -13,0 +14,4 @@
+const IO_DIR_INPUT_ALL: u8 = 0xFF;
+const IO_DIR_OUT_SFP_TX_DISABLE: u8 = !0x02;
+const IO_DIR_OUT_SFP_LED: u8 = !0x40;
+//SFP0 LED has different place in v1.1