doc: Fix RMT waveform path warnings

docs/en/api-reference/peripherals/rmt.rst

@@ -23,13 +23,13 @@ The signal, which consists of a series of pulses, is generated by RMT's transmit
 
         a [style=none, width=100, label="{11,high,7,low},\n{5,high,5,low},\n..."]
         b [label="Waveform\nGenerator"]
-        c [style=none, label="", background="../_static/rmt-waveform.png"]
+        c [style=none, label="", background="../../../_static/rmt-waveform.png"]
         d [shape=beginpoint, label="mod"]
         e [style=none, width=60, height=40, label="Carrier\nenable"]
         f [label="Carrier\nGenerator"]
-        g [style=none, label="", background="../_static/rmt-carrier.png"]
+        g [style=none, label="", background="../../../_static/rmt-carrier.png"]
         h [shape=none]
-        o [style=none, label="", background="../_static/rmt-waveform-modulated.png"]
+        o [style=none, label="", background="../../../_static/rmt-waveform-modulated.png"]
 
         group {
             label = Input
@@ -63,7 +63,7 @@ The reverse operation is performed by the receiver, where a series of pulses is
         e -- f;
         f -> b [folded];
 
-        a [style=none, label="", background="../_static/rmt-waveform.png"]
+        a [style=none, label="", background="../../../_static/rmt-waveform.png"]
         b [label=Filter]
         c [label="Edge\nDetect"]
         d [style=none, width=100, label="{11,high,7,low},\n{5,high,5,low},\n..."]