perf tools: Add empty Build files for architectures lacking them

perf currently fails to build on MIPS as there is no
tools/perf/arch/mips/Build file.  Adding an empty file fixes this as
there are no MIPS-specific sources to build.

It looks like the same is needed for Alpha and PA-RISC, though I
haven't been able to test those.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 5e8c0fb6a957 ("perf build: Add arch x86 objects building")
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1438704627.7315.2.camel@decadent.org.uk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/arch/alpha/Build b/tools/perf/arch/alpha/Build
new file mode 100644 (file)
index 0000000..1bb8bf6
--- /dev/null
+++ b/tools/perf/arch/alpha/Build
@@ -0,0 +1 @@
+# empty

diff --git a/tools/perf/arch/mips/Build b/tools/perf/arch/mips/Build
new file mode 100644 (file)
index 0000000..1bb8bf6
--- /dev/null
+++ b/tools/perf/arch/mips/Build
@@ -0,0 +1 @@
+# empty

diff --git a/tools/perf/arch/parisc/Build b/tools/perf/arch/parisc/Build
new file mode 100644 (file)
index 0000000..1bb8bf6
--- /dev/null
+++ b/tools/perf/arch/parisc/Build
@@ -0,0 +1 @@
+# empty