Fix a typo that prevented setting CIRCUITPY_HASHLIB_MBEDTLS properly

Author: jepler

py/circuitpy_mpconfig.mk

@@ -295,7 +295,7 @@ CFLAGS += -DCIRCUITPY_GNSS=$(CIRCUITPY_GNSS)
 CIRCUITPY_HASHLIB ?= $(CIRCUITPY_WEB_WORKFLOW)
 CFLAGS += -DCIRCUITPY_HASHLIB=$(CIRCUITPY_HASHLIB)
 
-CIRCUITPY_HASHLIB_MBEDTLS ?= $(CIRCUTPY_HASHLIB)
+CIRCUITPY_HASHLIB_MBEDTLS ?= $(CIRCUITPY_HASHLIB)
 CFLAGS += -DCIRCUITPY_HASHLIB_MBEDTLS=$(CIRCUITPY_HASHLIB_MBEDTLS)
 
 # i.e., we need to include a subset of mbedtls only for hashlib's own needs