all: Rename the "NORETURN" macro to "MP_NORETURN".

This commit renames the NORETURN macro, indicating to the compiler
that a function does not return, into MP_NORETURN to maintain the same
naming convention of other similar macros.

To maintain compaitiblity with existing code NORETURN is aliased to
MP_NORETURN, but it is also deprecated for MicroPython v2.

This changeset was created using a similar process to
decf8e6a8b ("all: Remove the "STATIC"
macro and just use "static" instead."), with no documentation or python
scripts to change to reflect the new macro name.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

extmod/modtls_mbedtls.c

@@ -147,7 +147,7 @@ static const unsigned char *asn1_get_data(mp_obj_t obj, size_t *out_len) {
     return (const unsigned char *)str;
 }
 
-static NORETURN void mbedtls_raise_error(int err) {
+static MP_NORETURN void mbedtls_raise_error(int err) {
     // Handle special cases.
     if (err == MBEDTLS_ERR_SSL_ALLOC_FAILED) {
         mp_raise_OSError(MP_ENOMEM);