doc: scripts: redirects: fix redirect for led_strip samples

Since I have integrated some samples into samples/drivers/led_strip,
seting up redirection from the deleted apa102, lpd8806, and ws2812.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>
diff --git a/doc/_scripts/redirects.py b/doc/_scripts/redirects.py
index 87fc9ee..8cb81cd 100644
--- a/doc/_scripts/redirects.py
+++ b/doc/_scripts/redirects.py
@@ -172,6 +172,9 @@
     ('reference/usermode/syscalls', 'kernel/usermode/syscalls'),
     ('reference/util/index', 'kernel/util/index'),
     ('samples/drivers/kscan_touch', 'samples/subsys/input/input'),
+    ('samples/drivers/led_apa102/README', 'samples/drivers/led_strip/README'),
+    ('samples/drivers/led_lpd8806/README', 'samples/drivers/led_strip/README'),
+    ('samples/drivers/led_ws2812/README', 'samples/drivers/led_strip/README'),
     ('samples/net/cloud/google_iot_mqtt/README', 'samples/net/cloud/cloud'),
     ('samples/sensor/wsen_hids/README', 'samples/sensor/sensor'),
     ('samples/sensor/wsen_itds/README', 'samples/sensor/sensor'),