ARC: Build system: Makefiles, Kconfig, Linker script

Arnd in his review pointed out that arch Kconfig organisation has several
deficiencies:

* Build time entries for things which can be runtime extracted from DT
  (e.g. SDRAM size, core clk frequency..)
* Not multi-platform-image-build friendly (choice .. endchoice constructs)
* cpu variants support (750/770) is exclusive.

The first 2 have been fixed in subsequent patches.
Due to the nature of the 750 and 770, it is not possible to build for
both together, w/o special runtime glue code which would hurt
performance.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild
index a90a3c6..105ec11 100644
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -33,6 +33,7 @@
 generic-y += msgbuf.h
 generic-y += param.h
 generic-y += parport.h
+generic-y += pci.h
 generic-y += percpu.h
 generic-y += poll.h
 generic-y += posix_types.h