Fixed Incoherent notation for the RZX Gate api doc (Qiskit#12754)

* Fixed Incoherent notation for the RZX Gate api doc

* Delete reno

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Co-authored-by: Julien Gacon <gaconju@gmail.com>

qiskit/circuit/library/standard_gates/rzx.py

@@ -100,19 +100,19 @@ class RZXGate(Gate):
 
         .. math::
 
-            R_{ZX}(\theta = 0) = I
+            R_{ZX}(\theta = 0)\ q_0, q_1 = I
 
         .. math::
 
-            R_{ZX}(\theta = 2\pi) = -I
+            R_{ZX}(\theta = 2\pi)\ q_0, q_1 = -I
 
         .. math::
 
-            R_{ZX}(\theta = \pi) = -i X \otimes Z
+            R_{ZX}(\theta = \pi)\ q_0, q_1 = -i X \otimes Z
 
         .. math::
 
-            RZX(\theta = \frac{\pi}{2}) = \frac{1}{\sqrt{2}}
+            R_{ZX}(\theta = \frac{\pi}{2})\ q_0, q_1 = \frac{1}{\sqrt{2}}
                                     \begin{pmatrix}
                                         1  & 0 & -i & 0 \\
                                         0  & 1 & 0  & i \\