[Blackfin] arch: Fix bug - kernel build with Debug option enabled fails to boot up

writes to I/DMEM_CONTROL must be followed by SSYNC

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/arch/blackfin/kernel/cplb-nompu/cacheinit.c b/arch/blackfin/kernel/cplb-nompu/cacheinit.c
index 62cbba7..8a18399 100644
--- a/arch/blackfin/kernel/cplb-nompu/cacheinit.c
+++ b/arch/blackfin/kernel/cplb-nompu/cacheinit.c
@@ -42,6 +42,7 @@
 	ctrl = bfin_read_IMEM_CONTROL();
 	ctrl |= IMC | ENICPLB;
 	bfin_write_IMEM_CONTROL(ctrl);
+	SSYNC();
 }
 #endif
 
@@ -63,5 +64,6 @@
 	ctrl = bfin_read_DMEM_CONTROL();
 	ctrl |= DMEM_CNTR;
 	bfin_write_DMEM_CONTROL(ctrl);
+	SSYNC();
 }
 #endif