[adc_ctrl,dv] Make adc_ctrl_filter_cfg_t unpacked

The layout of this structure doesn't really matter and it gets
randomised (see e.g. adc_ctrl_env_cfg::filter_cfg), which will mean
that min_v and max_v are picked uniformly from [2^31, 2^31-1]. I
really don't believe that's intended.

Signed-off-by: Rupert Swarbrick <[email protected]>

Author: rswarbrick

hw/ip/adc_ctrl/dv/env/adc_ctrl_env_pkg.sv

@@ -81,7 +81,7 @@ package adc_ctrl_env_pkg;
   } adc_ctrl_filter_cond_e;
 
   // Filter configuration
-  typedef struct packed {
+  typedef struct {
     adc_ctrl_filter_cond_e cond;  // Condition
     int min_v;  // Minimum value
     int max_v;  // Maximum value