AdvancedParaEQ: cache getEQInfos result on the device

HeadsetActiveEQPreset.build runs before HeadsetAdvancedEQ.build and probes
each EQ slot via getCustomEQ, which needs the step_db from getEQInfos to
decode gain values. Without the cache, the first pass decoded gains as
all 0.0dB and logged a "no cached getEQInfos — gain values will be wrong"
warning. Cache the dict on device._advanced_eq_info as soon as we have it
so every later caller sees the right step_db.

lib/logitech_receiver/advanced_para_eq.py

@@ -127,6 +127,7 @@ def get_advanced_eq_info(device):
             ro_presets,
             custom_presets,
         )
+        device._advanced_eq_info = info
         return info
 
     # V0 / V1
@@ -156,6 +157,7 @@ def get_advanced_eq_info(device):
         gain_min,
         gain_max,
     )
+    device._advanced_eq_info = info
     return info