build: set DESTCPU correctly for 'make binary' on loongarch64

Signed-off-by: 吴小白 <[email protected]>

Makefile

@@ -934,6 +934,9 @@ else
 ifeq ($(findstring riscv64,$(UNAME_M)),riscv64)
 DESTCPU ?= riscv64
 else
+ifeq ($(findstring loongarch64,$(UNAME_M)),loongarch64)
+DESTCPU ?= loong64
+else
 DESTCPU ?= x86
 endif
 endif
@@ -947,6 +950,7 @@ endif
 endif
 endif
 endif
+endif
 ifeq ($(DESTCPU),x64)
 ARCH=x64
 else
@@ -971,6 +975,9 @@ else
 ifeq ($(DESTCPU),riscv64)
 ARCH=riscv64
 else
+ifeq ($(DESTCPU),loong64)
+ARCH=loong64
+else
 ARCH=x86
 endif
 endif
@@ -980,6 +987,7 @@ endif
 endif
 endif
 endif
+endif
 
 # node and v8 use different arch names (e.g. node 'x86' vs v8 'ia32').
 # pass the proper v8 arch name to $V8_ARCH based on user-specified $DESTCPU.