doc: remove 'reboot' command from ACRN shell user guide
The 'reboot' command from the ACRN shell has been removed. Remove the
corresponding documentation from the ACRN Shell user guide.
@@ -42,8 +42,6 @@ The ACRN hypervisor shell supports the following commands:
loglevels for the remaining areas will not be changed
* - cpuid <leaf> [subleaf]
- Display the CPUID leaf [subleaf], in hexadecimal
- * - reboot
- - Trigger a system reboot (immediately)
* - rdmsr [-p<pcpu_id>] <msr_index>
- Read the Model-Specific Register (MSR) at index ``msr_index`` (in
hexadecimal) for CPU ID ``pcpu_id``
