cleanup makefile and enable CGO_ENABLED=0 (#4598)

Makefile

@@ -1,58 +1,8 @@
-LDFLAGS := $(shell go run buildscripts/gen-ldflags.go)
 PWD := $(shell pwd)
 GOPATH := $(shell go env GOPATH)
+LDFLAGS := $(shell go run buildscripts/gen-ldflags.go)
 
 BUILD_LDFLAGS := '$(LDFLAGS)'
-TAG := latest
-
-HOST ?= $(shell uname)
-CPU ?= $(shell uname -m)
-
-# if no host is identifed (no uname tool)
-# we assume a Linux-64bit build
-ifeq ($(HOST),)
-  HOST = Linux
-endif
-
-# identify CPU
-ifeq ($(CPU), x86_64)
-  HOST := $(HOST)64
-else
-ifeq ($(CPU), amd64)
-  HOST := $(HOST)64
-else
-ifeq ($(CPU), i686)
-  HOST := $(HOST)32
-endif
-endif
-endif
-
-
-#############################################
-# now we find out the target OS for
-# which we are going to compile in case
-# the caller didn't yet define OS himself
-ifndef (OS)
-  ifeq ($(HOST), Linux64)
-    arch = gcc
-  else
-  ifeq ($(HOST), Linux32)
-    arch = 32
-  else
-  ifeq ($(HOST), Darwin64)
-    arch = clang
-  else
-  ifeq ($(HOST), Darwin32)
-    arch = clang
-  else
-  ifeq ($(HOST), FreeBSD64)
-    arch = gcc
-  endif
-  endif
-  endif
-  endif
-  endif
-endif
 
 all: install
 
@@ -117,7 +67,7 @@ coverage: build
 
 gomake-all: build
 	@echo "Installing minio at $(GOPATH)/bin/minio"
-	@go build --ldflags $(BUILD_LDFLAGS) -o $(GOPATH)/bin/minio
+	@CGO_ENABLED=0 go build --ldflags $(BUILD_LDFLAGS) -o $(GOPATH)/bin/minio
 
 pkg-add:
 	@echo "Adding new package $(PKG)"