docs(linux): Power_Management: Remove references to unsupported rtc commands

TI SDK doesnot support `freeze` and `disk` options of rtcwake. Remove
them to avoid confusion.

Signed-off-by: Vishal Mahaveer <[email protected]>

Author: vishalmti

source/linux/Foundational_Components/Power_Management/pm_wakeup_sources.rst

@@ -67,12 +67,6 @@ It's possible to use the SoC's internal RTC to wakeup the system using the comma
    - Suspend to RAM and wakeup after 10 seconds:
       rtcwake -m mem -s {{10}}
 
-   - Suspend to disk (higher power saving) and wakeup 15 minutes later:
-      rtcwake -m disk --date +{{15}}min
-
-   - Freeze the system (more efficient than suspend-to-RAM but version 3.9 or newer of the Linux kernel is required) and wakeup at a given date and time:
-      rtcwake -m freeze --date {{YYYYMMDDhhmm}}
-
    - Disable a previously set alarm:
       rtcwake -m disable