arm64: drop GZFLAGS definition and export

Drop the definition and export of GZFLAGS, which was never referenced
on arm64, and whose last recorded use in the ARM port (on which arm64
was based original) was removed by patch

commit 5e89d379edb5ae08b57f39dd8d91697275245cbf [*]
Author: Russell King <[e-mail]>
Date: Wed Oct 16 14:32:17 2002 +0100

[ARM] Convert ARM makefiles to new kbuild (Sam Ravnborg, Kai, rmk)

[*] git commit ID based on Thomas Gleixner's historical GIT repository at
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git

Signed-off-by: Ard Biesheuvel <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

arch/arm64/Makefile

···
 
 LDFLAGS_vmlinux	:=--no-undefined -X
 CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
-GZFLAGS		:=-9
 
 ifeq ($(CONFIG_RELOCATABLE), y)
 # Pass --no-apply-dynamic-relocs to restore pre-binutils-2.27 behaviour
···
 KBUILD_CPPFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 KBUILD_AFLAGS += -DKASAN_SHADOW_SCALE_SHIFT=$(KASAN_SHADOW_SCALE_SHIFT)
 
-export	TEXT_OFFSET GZFLAGS
+export	TEXT_OFFSET
 
 core-y		+= arch/arm64/
 libs-y		:= arch/arm64/lib/ $(libs-y)