enable sbrk() for everyone

The sbrk() function can be used to merely query sizes and for that, no-mmu
works the same as mmu.  It can also sometimes increase data segments on
no-mmu systems provided the trailing memory is free.  So, there is no real
reason to exclude this function for no-mmu ports.

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

extra/Configs/Config.in.arch

@@ -200,11 +200,6 @@ config UCLIBC_UCLINUX_BROKEN_MUNMAP
 	depends on !ARCH_USE_MMU
 	default y
 
-config EXCLUDE_BRK
-	bool
-	depends on !ARCH_USE_MMU
-	default y
-
 config HAVE_DOT_CONFIG
 	bool
 	default y

libc/sysdeps/linux/common/Makefile.in

@@ -10,10 +10,6 @@ COMMON_OUT := $(top_builddir)libc/sysdeps/linux/common
 
 CSRC := $(notdir $(wildcard $(COMMON_DIR)/*.c))
 
-ifeq ($(EXCLUDE_BRK),y)
-CSRC := $(filter-out sbrk.c,$(CSRC))
-endif
-
 ifneq ($(UCLIBC_HAS_LFS),y)
 CSRC_LFS := $(notdir $(wildcard $(COMMON_DIR)/*64.c))
 CSRC := $(filter-out llseek.c $(CSRC_LFS),$(CSRC))