feat(Makefile): add support for arch mips

Usage:
```sh
TARGET_OS=linux GOARCH=mipsle TARGET_MIPS=softfloat make cloudflared
```

Makefile

@@ -119,6 +119,11 @@ else
 	PACKAGE_ARCH := $(TARGET_ARCH)
 endif
 
+#basically for GOMIPS=softfloat
+ifneq ($(TARGET_MIPS), )
+	MIPS_COMMAND := GOMIPS=$(TARGET_MIPS)
+endif
+
 #for FIPS compliance, FPM defaults to MD5.
 RPM_DIGEST := --rpm-digest sha256
 
@@ -134,7 +139,7 @@ cloudflared:
 ifeq ($(FIPS), true)
 	$(info Building cloudflared with go-fips)
 endif
-	GOOS=$(TARGET_OS) GOARCH=$(TARGET_ARCH) $(ARM_COMMAND) go build -mod=vendor $(GO_BUILD_TAGS) $(LDFLAGS) $(IMPORT_PATH)/cmd/cloudflared
+	GOOS=$(TARGET_OS) GOARCH=$(TARGET_ARCH) $(ARM_COMMAND) $(MIPS_COMMAND) go build -mod=vendor $(GO_BUILD_TAGS) $(LDFLAGS) $(IMPORT_PATH)/cmd/cloudflared
 ifeq ($(FIPS), true)
 	./check-fips.sh cloudflared
 endif

build-packages.sh

@@ -10,7 +10,7 @@ export CGO_ENABLED=0
 export ARTIFACT_DIR=artifacts/
 mkdir -p $ARTIFACT_DIR
 
-linuxArchs=("386" "amd64" "arm" "armhf" "arm64")
+linuxArchs=("386" "amd64" "arm" "armhf" "arm64" "mipsel")
 export TARGET_OS=linux
 for arch in ${linuxArchs[@]}; do
     unset TARGET_ARM
@@ -27,6 +27,11 @@ for arch in ${linuxArchs[@]}; do
         export TARGET_ARCH=arm
         export TARGET_ARM=7 
     fi
+
+    ## Support for softmips builds 
+    if [[ $arch == mipsel ]] ; then
+        export GOMIPS=softfloat
+    fi
     
     make cloudflared-deb
     mv cloudflared\_$VERSION\_$arch.deb $ARTIFACT_DIR/cloudflared-linux-$arch.deb