remove unneeded LONGINT_IMPL logic

Author: jepler

ports/broadcom/mpconfigport.mk

@@ -1,19 +1,3 @@
-# Define an equivalent for MICROPY_LONGINT_IMPL, to pass to $(MPY-TOOL) in py/mkrules.mk
-# $(MPY-TOOL) needs to know what kind of longint to use (if any) to freeze long integers.
-# This should correspond to the MICROPY_LONGINT_IMPL definition in mpconfigport.h.
-
-ifeq ($(LONGINT_IMPL),NONE)
-MPY_TOOL_LONGINT_IMPL = -mlongint-impl=none
-endif
-
-ifeq ($(LONGINT_IMPL),MPZ)
-MPY_TOOL_LONGINT_IMPL = -mlongint-impl=mpz
-endif
-
-ifeq ($(LONGINT_IMPL),LONGLONG)
-MPY_TOOL_LONGINT_IMPL = -mlongint-impl=longlong
-endif
-
 # All broadcom ports have longints.
 LONGINT_IMPL = MPZ