package/micropython: define MICROPY_NLR_SETJMP for xtensa

As suggested on https://github.com/micropython/micropython/issues/6551
define MICROPY_NLR_SETJMP to avoid the xtensa specific implementation
of nlr_push.

Fixes:
- http://autobuild.buildroot.net/results/5fc8669b5c768ccfc02bd20d1159bce7fe43683e

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 9fd9f4e6752fd0931fa5cc287bf0e6cd598c36a1)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/micropython/micropython.mk

@@ -21,6 +21,11 @@ ifeq ($(BR2_i386)$(BR2_x86_64)$(BR2_arm)$(BR2_armeb),)
 MICROPYTHON_CFLAGS = -DMICROPY_GCREGS_SETJMP=1
 endif
 
+# xtensa has problems with nlr_push, use setjmp based implementation instead
+ifeq ($(BR2_xtensa),y)
+MICROPYTHON_CFLAGS = -DMICROPY_NLR_SETJMP=1
+endif
+
 # When building from a tarball we don't have some of the dependencies that are in
 # the git repository as submodules
 MICROPYTHON_MAKE_OPTS += \