stmhal: Disable MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE.

It uses RAM and on pyboard we are generally tight on RAM, so disable
this optimisation for general builds.  If users need the speed then
they can build their own version.  Maybe in the future we can have
different versions of pyboard firmware built with different tradeoffs.

stmhal/mpconfigport.h

@@ -42,7 +42,7 @@
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_MPZ)
 #define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_FLOAT)
 #define MICROPY_OPT_COMPUTED_GOTO   (1)
-#define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (1)
+#define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (0)
 /* Enable FatFS LFNs
     0: Disable LFN feature.
     1: Enable LFN with static working buffer on the BSS. Always NOT reentrant.