uapi: Allow automatic generation of uapi/asm/ header files

Several arch/*/include/uapi/asm/* header simply include the
corresponding <asm-generic/*> file. This patch allows such files to be
specified in uapi/asm/Kbuild via "generic-y += ..." to be automatically
generated (similar to asm/Kbuild).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>

Makefile

diff --git a/Makefile b/Makefile
index 5be2ee8..366d0ab 100644
--- a/Makefile
+++ b/Makefile
@@ -437,7 +437,9 @@
 PHONY += asm-generic
 asm-generic:
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
-	            obj=arch/$(SRCARCH)/include/generated/asm
+	            src=asm obj=arch/$(SRCARCH)/include/generated/asm
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
+	            src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
 
 # To make sure we do not include .config for any of the *config targets
 # catch them early, and hand them over to scripts/kconfig/Makefile