ad_gmsl2eth_sl: Update README to latest state

Signed-off-by: alin724 <alin-tudor.sferle@analog.com>

Author: alin724

projects/ad_gmsl2eth_sl/k26/README.md

@@ -18,8 +18,9 @@ The +VCC_SOM voltage is 5V and the SOM connectors voltages can be found in the t
 This project uses [Corundum NIC](https://github.com/corundum/corundum) and it needs to be cloned alongside this repository.
 
 ```
-git clone https://github.com/corundum/corundum.git
-git checkout ed4a26e2cbc0a429c45d5cd5ddf1177f86838914
+hdl/../> git clone https://github.com/ucsdsysnet/corundum.git
+corundum/> git checkout 37f2607
+corundum/> git apply ../hdl/library/corundum/patch_axis_xgmii_rx_64.patch
 cd hdl/projects/ad_gmsl2eth_sl/k26
 make
 ```