qcacld-3.0: Remove unused SPECTRAL_USE_NETLINK_SOCKETS macro

Kbuild currently passes the macro SPECTRAL_USE_NETLINK_SOCKETS to the
compiler.  However this macro is now obsolete, so remove it.

Change-Id: Id88028cceddcaaf8f35c708451fa5bf21c4695dd
CRs-Fixed: 2220919

Kbuild

@@ -1877,7 +1877,6 @@ CDEFINES :=	-DANI_LITTLE_BYTE_ENDIAN \
 		-DCONFIG_HDD_INIT_WITH_RTNL_LOCK \
 		-DCONVERGED_TDLS_ENABLE \
 		-DWLAN_CONV_SPECTRAL_ENABLE \
-		-DSPECTRAL_USE_NETLINK_SOCKETS \
 		-DWLAN_SPECTRAL_ENABLE \
 		-DWMI_CMD_STRINGS