micropython: Add upstream patch to fix 64-bit builds

Fixes the following error when building for a 64-bit target

  ../py/objint_mpz.c:54:5: error: right shift count >= width of type [-Werror]
       (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 4) & DIG_MASK,
       ^
  ../py/objint_mpz.c:54:5: error: initializer element is not constant
  ../py/objint_mpz.c:54:5: error: (near initialization for 'maxsize_dig[4]')

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Tested-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>