ppc4xx: HCU4/5. Use FLASH_CFI_LEGACY

Cleanup: Remove custom flash driver for 8 bit boot-eprom and replace it with
the FLASH_CFI_LEGACY et al. config options.

Signed-off-by: Niklaus Giger <niklaus.giger@netstal.com>
diff --git a/board/netstal/hcu4/Makefile b/board/netstal/hcu4/Makefile
index 3d1d65d..53df61e 100644
--- a/board/netstal/hcu4/Makefile
+++ b/board/netstal/hcu4/Makefile
@@ -23,7 +23,7 @@
 LIB	= $(obj)lib$(BOARD).a
 
 # NOBJS : Netstal common objects
-NOBJS	= fixed_sdram.o hcu_flash.o nm_bsp.o
+NOBJS	= fixed_sdram.o nm_bsp.o
 COBJS	= $(BOARD).o
 SOBJS	=