arm64: remove special treatment for the link order of head.o

arm64: remove special treatment for the link order of head.o

In the previous discussion (see the Link tag), Ard pointed out that
arm/arm64/kernel/head.o does not need any special treatment - the only
piece that must appear right at the start of the binary image is the
image header which is emitted into .head.text.

The linker script does the right thing to do. The build system does
not need to manipulate the link order of head.o.

Link: https://lore.kernel.org/lkml/CAMj1kXH77Ja8bSsq2Qj8Ck9iSZKw=1F8Uy-uAWGVDm4-CG=EuA@mail.gmail.com/
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Link: https://lore.kernel.org/r/20221012233500.156764-1-masahiroy@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>