updating mpfs: update Ubuntu Server image name for Jammy release

The Icicle Kit Ubuntu Server image name change slightly between the
daily builds and the official Ubuntu Jammy release page. Update the
document to reflect this change.

Signed-off-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>

reference-designs-fpga-and-development-kits/updating-mpfs-kit.md

@@ -228,7 +228,7 @@ A FlashPro Express programming job file is provided as an asset with each releas
 2. Extract the image using a file archiver such as 7-Zip on Windows. Alternatively, if using Linux, the image can be extracted using the following command:
 
     ```bash
-    unxz jammy-preinstalled-server-riscv64+icicle.img.xz
+    unxz ubuntu-22.04.2-preinstalled-server-riscv64+icicle.img.xz
     ```
 
 3. Program the image extracted in the step above to either the on-board eMMC or an SD card.
@@ -239,7 +239,7 @@ A FlashPro Express programming job file is provided as an asset with each releas
     Alternatively, if using Linux, the image can be programmed using from using the `dd` command:
 
     ```bash
-    sudo dd if=jammy-preinstalled-server-riscv64+icicle.img of=/dev/sdX bs=1M conv=fsync
+    sudo dd if=ubuntu-22.04.2-preinstalled-server-riscv64+icicle.img of=/dev/sdX bs=1M conv=fsync
     ```
 
     You will have to replace /dev/sdX by the actual device name of your SD card. Please, be especially cautious not to overwrite the wrong drive as this cannot be undone.