blackfin: convert blackfin board_f and board_r to use generic board init functions

- move blackfin specific cpu init code from blackfin board.c to cpu.c
- remove blackfin specific board init code and invoke generic board_f fron cpu init entry
- rename section name bss_vma to bss_start in order to match the generic board init code
- add a fake relocate_code function to set up the new stack only

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
diff --git a/arch/blackfin/lib/Makefile b/arch/blackfin/lib/Makefile
index 4ba7bf6..b534a98 100644
--- a/arch/blackfin/lib/Makefile
+++ b/arch/blackfin/lib/Makefile
@@ -9,11 +9,6 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-# Unnecessary.
-# Use CONFIG_SYS_BOARD instead of BFIN_BOARD_NAME
-# and delete this.
-ccflags-y += -DBFIN_BOARD_NAME='"$(BOARD)"'
-
 obj-y	+= ins.o
 obj-y	+= memcmp.o
 obj-y	+= memcpy.o
@@ -21,7 +16,6 @@
 obj-y	+= memset.o
 obj-y	+= outs.o
 obj-$(CONFIG_CMD_KGDB) += __kgdb.o
-obj-y	+= board.o
 obj-y	+= boot.o
 obj-y	+= cache.o
 obj-y	+= clocks.o
@@ -30,3 +24,4 @@
 obj-y	+= muldi3.o
 obj-$(CONFIG_HAS_POST) += post.o
 obj-y	+= string.o
+obj-y	+= sections.o