Documentation/gpu: Add entries to amdgpu glossary

Add missing acronyms to the amdgppu glossary.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/1939
Acked-by: Christian König <[e-mail]>
Signed-off-by: Tales Lelo da Aparecida <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

Documentation/gpu/amdgpu/amdgpu-glossary.rst

···
 
 .. glossary::
 
+    active_cu_number
+      The number of CUs that are active on the system.  The number of active
+      CUs may be less than SE * SH * CU depending on the board configuration.
+
     CP
       Command Processor
 
     CPLIB
       Content Protection Library
+
+    CU
+      Compute Unit
 
     DFS
       Digital Frequency Synthesizer
···
 
     SDMA
       System DMA
+
+    SE
+      Shader Engine
+
+    SH
+      SHader array
 
     SMU
       System Management Unit