arm64: pi: use 'targets' instead of extra-y in Makefile

%.pi.o files are built as prerequisites of other objects.
There is no need to use extra-y, which is planned for deprecation.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20250602180937.528459-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: masahir0y

arch/arm64/kernel/pi/Makefile

@@ -41,4 +41,4 @@ obj-y					:= idreg-override.pi.o \
 obj-$(CONFIG_RELOCATABLE)		+= relocate.pi.o
 obj-$(CONFIG_RANDOMIZE_BASE)		+= kaslr_early.pi.o
 obj-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS)	+= patch-scs.pi.o
-extra-y					:= $(patsubst %.pi.o,%.o,$(obj-y))
+targets					:= $(patsubst %.pi.o,%.o,$(obj-y))