ARC: [Review] Multi-platform image #4: Isolate platform headers

-Top level ARC makefile removes -I for platform headers
-asm/irq.h no longer includes plat/irq.h

-platform makefile adds -I for it's specfic platform headers
-platform code to directly include it's plat/irq.h

-Linker script needed plat/memmap.h for CCM info, already in .config

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arc/plat-arcfpga/Makefile b/arch/arc/plat-arcfpga/Makefile
index 2a828be..a44e22e 100644
--- a/arch/arc/plat-arcfpga/Makefile
+++ b/arch/arc/plat-arcfpga/Makefile
@@ -6,5 +6,7 @@
 # published by the Free Software Foundation.
 #
 
+KBUILD_CFLAGS	+= -Iarch/arc/plat-arcfpga/include
+
 obj-y := platform.o irq.o
 obj-$(CONFIG_SMP)		+= smp.o