samples: bluetooth: fast_pair: locator_tag: add PM note for nRF54H20 DK

Added a note to the documentation of the Fast Pair Locator Tag sample
that notifies the user about the increased power consumption for the
nRF54H20 DK target.

Signed-off-by: Kamil Piszczek <[email protected]>

Author: kapi-no

samples/bluetooth/fast_pair/locator_tag/README.rst

@@ -24,6 +24,10 @@ The sample supports the following development kits:
 
 .. table-from-sample-yaml::
 
+.. note::
+   In case of the :ref:`zephyr:nrf54h20dk_nrf54h20` board target, the application still has high power consumption as the Bluetooth LE controller running on the radio core requires disabling MRAM latency (:kconfig:option:`CONFIG_MRAM_LATENCY_AUTO_REQ`).
+   Enabling MRAM latency makes the Bluetooth LE controller unstable.
+
 Overview
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