[media] DocBook: add xrefs for enum fe_type

The only enum that was missing xrefs at frontend.h is fe_type.
Add xrefs for them.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

Documentation/DocBook/media/dvb/frontend_legacy_api.xml

···
   </thead>
   <tbody valign="top">
   <row>
-     <entry id="FE_QPSK"><constant>FE_QPSK</constant></entry>
+     <entry id="FE-QPSK"><constant>FE_QPSK</constant></entry>
      <entry>For DVB-S standard</entry>
      <entry><constant>SYS_DVBS</constant></entry>
   </row>
   <row>
-     <entry id="FE_QAM"><constant>FE_QAM</constant></entry>
+     <entry id="FE-QAM"><constant>FE_QAM</constant></entry>
      <entry>For DVB-C annex A standard</entry>
      <entry><constant>SYS_DVBC_ANNEX_A</constant></entry>
   </row>
   <row>
-     <entry id="FE_OFDM"><constant>FE_OFDM</constant></entry>
+     <entry id="FE-OFDM"><constant>FE_OFDM</constant></entry>
      <entry>For DVB-T standard</entry>
      <entry><constant>SYS_DVBT</constant></entry>
   </row>
   <row>
-     <entry id="FE_ATSC"><constant>FE_ATSC</constant></entry>
+     <entry id="FE-ATSC"><constant>FE_ATSC</constant></entry>
      <entry>For ATSC standard (terrestrial) or for DVB-C Annex B (cable) used in US.</entry>
      <entry><constant>SYS_ATSC</constant> (terrestrial) or <constant>SYS_DVBC_ANNEX_B</constant> (cable)</entry>
   </row>

include/uapi/linux/dvb/frontend.h

···
 
 #include <linux/types.h>
 
-typedef enum fe_type {
+enum fe_type {
 	FE_QPSK,
 	FE_QAM,
 	FE_OFDM,
 	FE_ATSC
-} fe_type_t;
+};
+
+typedef enum fe_type fe_type_t;
 
 
 enum fe_caps {