Documentation: amd-sbi: Wrap miscdevice listing snippet in literal code block

Device file listing (ls output) is shown as long-running paragraph
instead. Wrap it in literal code block.

Fixes: 4d95514d14e874 ("misc: amd-sbi: Add document for AMD SB IOCTL description")
Signed-off-by: Bagas Sanjaya <[e-mail]>
Reviewed-by: Randy Dunlap <[e-mail]>
Tested-by: Randy Dunlap <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>
Message-ID: <[e-mail]>

Documentation/misc-devices/amd-sbi.rst

···
 Register sets is common across APML protocols. IOCTL is providing synchronization
 among protocols as transactions may create race condition.
 
-$ ls -al /dev/sbrmi-3c
-crw-------    1 root     root       10,  53 Jul 10 11:13 /dev/sbrmi-3c
+.. code-block:: bash
+
+   $ ls -al /dev/sbrmi-3c
+   crw-------    1 root     root       10,  53 Jul 10 11:13 /dev/sbrmi-3c
 
 apml_sbrmi driver registers hwmon sensors for monitoring power_cap_max,
 current power consumption and managing power_cap.