archs: replace unifdef-y with header-y

unifdef-y and header-y have same semantic, so drop unifdef-y

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index b7c8f18..e423def 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -1,11 +1,10 @@
 include include/asm-generic/Kbuild.asm
 
+header-y += compiler.h
+header-y += console.h
+header-y += fpu.h
 header-y += gentrap.h
-header-y += regdef.h
 header-y += pal.h
 header-y += reg.h
-
-unifdef-y += console.h
-unifdef-y += fpu.h
-unifdef-y += sysinfo.h
-unifdef-y += compiler.h
+header-y += regdef.h
+header-y += sysinfo.h