hwmon: (amd_energy) Update driver documentation

Update the documentation with the newly added features
* Set the accumulation interval based on resolution

Signed-off-by: Naveen Krishna Chatradhi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/hwmon/amd_energy.rst

···
 running during probe, wakes up every 100secs and stops running
 when driver is removed.
 
+Frequency of the accumulator thread is set during the probe
+based on the chosen energy unit resolution. For example
+A. fine grain (1.625 micro J)
+B. course grain (0.125 milli J)
+
 A socket and core energy read would return the current register
 value added to the respective energy accumulator.