Blackfin: config.mk: drop manual stripping of config vars

Now that the common code takes care of stripping away quotes and such
from numeric options, we no longer need to do so ourselves.  So drop
the custom code we have in the Blackfin config.mk.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/config.mk

@@ -26,8 +26,6 @@ CROSS_COMPILE ?= bfin-uclinux-
 STANDALONE_LOAD_ADDR = 0x1000 -m elf32bfin
 
 CONFIG_BFIN_BOOT_MODE := $(strip $(subst ",,$(CONFIG_BFIN_BOOT_MODE)))
-CONFIG_ENV_OFFSET := $(strip $(subst ",,$(CONFIG_ENV_OFFSET)))
-CONFIG_ENV_SIZE := $(strip $(subst ",,$(CONFIG_ENV_SIZE)))
 
 PLATFORM_RELFLAGS += -ffixed-P3 -fomit-frame-pointer -mno-fdpic
 PLATFORM_CPPFLAGS += -DCONFIG_BLACKFIN