systool: add page (#13096)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>
Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/linux/systool.md

@@ -0,0 +1,17 @@
+# systool
+
+> View system device information by bus, and classes.
+> This command is part of the `sysfs` package.
+> More information: <https://github.com/linux-ras/sysfsutils>.
+
+- List all attributes of devices of a bus (eg. `pci`, `usb`). View all buses using `ls /sys/bus`:
+
+`systool -b {{bus}} -v`
+
+- List all attributes of a class of devices (eg. `drm`, `block`). View all classes using `ls /sys/class`:
+
+`systool -c {{class}} -v`
+
+- Show only device drivers of a bus (eg. `pci`, `usb`):
+
+`systool -b {{bus}} -D`