lib/circbuf: Make circbuf selectable symbol
It is currenly only used from usbtty driver but make it properly
selectable via Kconfig symbol, for future usage.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
diff --git a/lib/Makefile b/lib/Makefile
index 7950e84..f223892 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -29,7 +29,13 @@
obj-y += charset.o
endif
endif
-obj-$(CONFIG_USB_TTY) += circbuf.o
+
+ifdef CONFIG_USB_TTY
+obj-y += circbuf.o
+else
+obj-$(CONFIG_CIRCBUF) += circbuf.o
+endif
+
obj-y += crc8.o
obj-y += crc16.o
obj-$(CONFIG_ERRNO_STR) += errno_str.o