default to enabling SHA256 when hashlib is enabled

Author: samblenny

py/circuitpy_mpconfig.mk

@@ -343,7 +343,7 @@ CFLAGS += -DCIRCUITPY_HASHLIB_MBEDTLS=$(CIRCUITPY_HASHLIB_MBEDTLS)
 CIRCUITPY_HASHLIB_MBEDTLS_ONLY ?= $(call enable-if-all,$(CIRCUITPY_HASHLIB_MBEDTLS) $(call enable-if-not,$(CIRCUITPY_SSL)))
 CFLAGS += -DCIRCUITPY_HASHLIB_MBEDTLS_ONLY=$(CIRCUITPY_HASHLIB_MBEDTLS_ONLY)
 
-CIRCUITPY_HASHLIB_SHA256 ?= 0
+CIRCUITPY_HASHLIB_SHA256 ?= $(CIRCUITPY_HASHLIB)
 CFLAGS += -DCIRCUITPY_HASHLIB_SHA256=$(CIRCUITPY_HASHLIB_SHA256)
 
 CIRCUITPY_I2CTARGET ?= $(CIRCUITPY_FULL_BUILD)