Remove raspi-cpu

This command doesn't work on Raspis with UEFI enabled. However when I use btm
it can display the temperature just fine.

modules/hardware/raspi4/raspi-base.nix

@@ -116,9 +116,6 @@ in {
       test-sd-card
     ];
     environment.shellAliases = {
-      raspi-cpu = ''
-        sudo vcgencmd get_throttled && sudo vcgencmd measure_temp
-      '';
       raspi-firmware-update = ''
         sudo mkdir -p /mnt/firmware && \
         sudo mount /dev/disk/by-label/FIRMWARE /mnt/firmware && \