selftests: breakpoints: fix installing error on the architecture except x86

# Taken from perf makefile

uname_M := $(shell uname -m 2>/dev/null || echo not)

ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/)

ifeq ($(ARCH),i386)

        ARCH := x86

endif

ifeq ($(ARCH),x86_64)

	ARCH := x86

endif

ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)

all:

ifeq ($(ARCH),x86)

	gcc breakpoint_test.c -o breakpoint_test

else

	echo "Not an x86 target, can't build breakpoints selftests"

TEST_PROGS := breakpoint_test

endif

TEST_PROGS := breakpoint_test

all:

include ../lib.mk