Blackfin arch: fix bugs and unify BFIN_KERNEL_CLOCK option

 - remove duplicated code and headers
 - add option allowing arbitrary SDRAM/DDR Timing parameters.
 - mark automatically calculated timings as EXPERIMENTAL
 - fix comment header block

Related to BUGs:
 - kernel boot up fails with CONFIG_BFIN_KERNEL_CLOCK item on.
 - kernel does not boot if re-program clocks

[ Mike Frysinger <vapier.adi@gmail.com>
 - fix comment header
 - mark do_sync static
 - document the DMA shutdown
 - simplify SIC_IWR handling
 - fix ANOMALY_05000265 handling to work as intended ]

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/Makefile b/arch/blackfin/Makefile
index 2faad12..558241e 100644
--- a/arch/blackfin/Makefile
+++ b/arch/blackfin/Makefile
@@ -91,7 +91,7 @@
 CHECKFLAGS_SILICON = $(shell echo "" | $(CPP) $(KBUILD_CFLAGS) -dD - 2>/dev/null | awk '$$2 == "__SILICON_REVISION__" { print $$3 }')
 CHECKFLAGS += -D__SILICON_REVISION__=$(CHECKFLAGS_SILICON) -Dl1_text=__used__
 
-head-y   := arch/$(ARCH)/mach-$(MACHINE)/head.o arch/$(ARCH)/kernel/init_task.o
+head-y   := arch/$(ARCH)/kernel/init_task.o
 
 core-y   += arch/$(ARCH)/kernel/ arch/$(ARCH)/mm/ arch/$(ARCH)/mach-common/