wifi: ath12k: Prefer {} to {0} in initializers

Prefer {} to {0} in initializers since {} works even when the first
member is not a scalar.

Generated using:
sed -i 's/{[[:space:]]*0[[:space:]]*}/{}/g' drivers/net/wireless/ath/ath12k/*

Compile tested only.

Link: https://patch.msgid.link/20250720-ath12k-zero-brace-v1-1-d8c8ca9d40a8@oss.qualcomm.com


Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>