kbuild: only one call for include/ in make headers_*

Move it to the top-level file to decide if we install/check
the generic headers or the arch specific headers.

This revealed a long standing bug where "make headers_check_all"
relied on the files in asm/ for the current architecture.
So make headers_check_all is now broken by this commit.

In addition:

o add a simpler way to detect if an arch support
  exporting header files.

o add 'set -e;' so we error out early if
  make headers_check_all fails.

o add sparc64 and cris to arch we do not process
  in make headers_*_all because:

    sparc64 - use sparc to export headers
    cris    - is know seriously broken

Includes suggestions from: David Woodhouse
<dwmw2@infradead.org>.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: David Woodhouse <dwmw2@infradead.org>
diff --git a/include/Kbuild b/include/Kbuild
index bdca155..d8c3e3c 100644
--- a/include/Kbuild
+++ b/include/Kbuild
@@ -1,3 +1,6 @@
+# Top-level Makefile calls into asm-$(ARCH)
+# List only non-arch directories below
+
 header-y += asm-generic/
 header-y += linux/
 header-y += sound/
@@ -5,5 +8,3 @@
 header-y += rdma/
 header-y += video/
 header-y += drm/
-
-header-y += asm-$(ARCH)/