Drop superseeded CRDA utility (#1452)

The CRDA (Central Regulatory Domain Agent) utility has been used as a
user space helper to load regulatory information for WiFi drivers.
However, since Linux 4.15 the kernel can load the regulatory information
directly from a signed firmware file "regulatory.db".

The regulatory.db file is provided by the WIRELESS_REGDB package, which
has been already installed since its a dependency of CRDA.

Drop CRDA and select WIRELESS_REGDB package explicitly to make sure the
regulatory.db file is present.

buildroot-external/kernel/hassos.config

@@ -42,6 +42,7 @@ CONFIG_WEXT_CORE=y
 CONFIG_WEXT_PROC=y
 CONFIG_CFG80211=m
 CONFIG_CFG80211_WEXT=y
+# CONFIG_CFG80211_CRDA_SUPPORT is not set
 
 CONFIG_CIFS=m
 CONFIG_CIFS_XATTR=y