build: set DESTCPU correctly for 'make binary' on Apple Silicon

PR-URL: #40147
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>

Makefile

@@ -827,6 +827,9 @@ else
 ifeq ($(findstring s390,$(UNAME_M)),s390)
 DESTCPU ?= s390
 else
+ifeq ($(findstring arm64,$(UNAME_M)),arm64)
+DESTCPU ?= arm64
+else
 ifeq ($(findstring arm,$(UNAME_M)),arm)
 DESTCPU ?= arm
 else
@@ -850,6 +853,7 @@ endif
 endif
 endif
 endif
+endif
 ifeq ($(DESTCPU),x64)
 ARCH=x64
 else