.gitignore: remove too obvious comments

Some .gitignore files have comments like "Generated files",
"Ignore generated files" at the header part, but they are
too obvious.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

certs/.gitignore

-#
-# Generated files
-#
 x509_certificate_list

drivers/atm/.gitignore

-# Ignore generated files
 fore200e_mkfirm
 fore200e_pca_fw.c
 pca200e.bin

drivers/video/logo/.gitignore

-#
-# Generated files
-#
 *_mono.c
 *_vga16.c
 *_clut224.c

kernel/.gitignore

-#
-# Generated files
-#
 kheaders.md5
 timeconst.h
 hz.bc

lib/.gitignore

-#
-# Generated files
-#
 gen_crc32table
 gen_crc64table
 crc32table.h

scripts/.gitignore

-#
-# Generated files
-#
 bin2c
 kallsyms
 unifdef

scripts/kconfig/.gitignore

-#
-# Generated files
-#
 *.moc
 *conf-cfg
 

scripts/selinux/mdp/.gitignore

-# Generated file
 mdp

security/apparmor/.gitignore

-#
-# Generated include files
-#
 net_names.h
 capability_names.h
 rlim_names.h

sound/oss/.gitignore

-#Ignore generated files
 pss_boot.h
 trix_boot.h