hexagon: ignore vmlinux.lds

After building allmodconfig, there is an untracked vmlinux.lds file in
arch/hexagon/kernel:

$ git ls-files . --exclude-standard --others
arch/hexagon/kernel/vmlinux.lds

Ignore it as all other architectures have.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Nathan Chancellor <[e-mail]>
Cc: Brian Cain <[e-mail]>
Cc: Nick Desaulniers <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/hexagon/kernel/.gitignore

···
+vmlinux.lds