KVM: arm64: nvhe: Rename confusing obj-y

This Makefile appends several objects to obj-y from line 15, but none
of them is linked to vmlinux in an ordinary way.

obj-y is overwritten at line 30:

  obj-y := kvm_nvhe.o

So, kvm_nvhe.o is the only object directly linked to vmlinux.

Replace the abused obj-y with hyp-obj-y.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220613092026.1705630-1-masahiroy@kernel.org