media: dvb/frontend.h: fix kernel-doc warnings

scripts/kernel-doc spouts multiple warnings, so fix them:

include/uapi/linux/dvb/frontend.h:399: warning: Enum value 'QAM_1024' not described in enum 'fe_modulation'
include/uapi/linux/dvb/frontend.h:399: warning: Enum value 'QAM_4096' not described in enum 'fe_modulation'
frontend.h:286: warning: contents before sections
frontend.h:780: warning: missing initial short description on line:
 * enum atscmh_rs_code_mode

Fixes: 8220ead ("media: dvb/frontend.h: document the uAPI file")
Fixes: 6508a50 ("media: dvb: add DVB-C2 and DVB-S2X parameter values")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Robert Schlabbach <robert_s@gmx.net>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

include/uapi/linux/dvb/frontend.h

@@ -282,7 +282,6 @@ enum fe_spectral_inversion {
 /**
  * enum fe_code_rate - Type of Forward Error Correction (FEC)
  *
- *
  * @FEC_NONE: No Forward Error Correction Code
  * @FEC_1_2:  Forward Error Correction Code 1/2
  * @FEC_2_3:  Forward Error Correction Code 2/3
@@ -363,8 +362,8 @@ enum fe_code_rate {
  * @APSK_32:	32-APSK modulation
  * @DQPSK:	DQPSK modulation
  * @QAM_4_NR:	4-QAM-NR modulation
- * @QAM-1024:	1024-QAM modulation
- * @QAM-4096:	4096-QAM modulation
+ * @QAM_1024:	1024-QAM modulation
+ * @QAM_4096:	4096-QAM modulation
  * @APSK_8_L:	8APSK-L modulation
  * @APSK_16_L:	16APSK-L modulation
  * @APSK_32_L:	32APSK-L modulation
@@ -777,7 +776,7 @@ enum atscmh_rs_frame_mode {
 };
 
 /**
- * enum atscmh_rs_code_mode
+ * enum atscmh_rs_code_mode - ATSC-M/H Reed Solomon modes
  * @ATSCMH_RSCODE_211_187:	Reed Solomon code (211,187).
  * @ATSCMH_RSCODE_223_187:	Reed Solomon code (223,187).
  * @ATSCMH_RSCODE_235_187:	Reed Solomon code (235,187).