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>

py/modmath.c

@@ -37,7 +37,7 @@
 #define MP_PI_4 MICROPY_FLOAT_CONST(0.78539816339744830962)
 #define MP_3_PI_4 MICROPY_FLOAT_CONST(2.35619449019234492885)
 
-static NORETURN void math_error(void) {
+static MP_NORETURN void math_error(void) {
     mp_raise_ValueError(MP_ERROR_TEXT("math domain error"));
 }