py/modmath: Make log2, log10 and hyperbolic funcs be SPECIAL_FUNCTIONS.

Will be included only when MICROPY_PY_MATH_SPECIAL_FUNCTIONS is enabled.

Also covers cmath module (but only log10 is there at the moment).
diff --git a/py/modcmath.c b/py/modcmath.c
index 089210d..83d8677 100644
--- a/py/modcmath.c
+++ b/py/modcmath.c
@@ -86,6 +86,7 @@
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mp_cmath_log_obj, mp_cmath_log);
 
+#if MICROPY_PY_MATH_SPECIAL_FUNCTIONS
 /// \function log10(z)
 /// Return the base-10 logarithm of `z`.  The branch cut is along the negative real axis.
 STATIC mp_obj_t mp_cmath_log10(mp_obj_t z_obj) {
@@ -94,6 +95,7 @@
     return mp_obj_new_complex(0.5 * MICROPY_FLOAT_C_FUN(log10)(real*real + imag*imag), 0.4342944819032518 * MICROPY_FLOAT_C_FUN(atan2)(imag, real));
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mp_cmath_log10_obj, mp_cmath_log10);
+#endif
 
 /// \function sqrt(z)
 /// Return the square-root of `z`.
@@ -133,7 +135,9 @@
     { MP_OBJ_NEW_QSTR(MP_QSTR_rect), (mp_obj_t)&mp_cmath_rect_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_exp), (mp_obj_t)&mp_cmath_exp_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_log), (mp_obj_t)&mp_cmath_log_obj },
+    #if MICROPY_PY_MATH_SPECIAL_FUNCTIONS
     { MP_OBJ_NEW_QSTR(MP_QSTR_log10), (mp_obj_t)&mp_cmath_log10_obj },
+    #endif
     { MP_OBJ_NEW_QSTR(MP_QSTR_sqrt), (mp_obj_t)&mp_cmath_sqrt_obj },
     //{ MP_OBJ_NEW_QSTR(MP_QSTR_acos), (mp_obj_t)&mp_cmath_acos_obj },
     //{ MP_OBJ_NEW_QSTR(MP_QSTR_asin), (mp_obj_t)&mp_cmath_asin_obj },
diff --git a/py/modmath.c b/py/modmath.c
index 423ad4c..b7aa592 100644
--- a/py/modmath.c
+++ b/py/modmath.c
@@ -68,7 +68,6 @@
 #if MICROPY_PY_MATH_SPECIAL_FUNCTIONS
 /// \function expm1(x)
 MATH_FUN_1(expm1, expm1)
-#endif
 /// \function log2(x)
 MATH_FUN_1(log2, log2)
 /// \function log10(x)
@@ -85,6 +84,7 @@
 MATH_FUN_1(asinh, asinh)
 /// \function atanh(x)
 MATH_FUN_1(atanh, atanh)
+#endif
 /// \function cos(x)
 MATH_FUN_1(cos, cos)
 /// \function sin(x)
@@ -198,6 +198,7 @@
     { MP_OBJ_NEW_QSTR(MP_QSTR_expm1), (mp_obj_t)&mp_math_expm1_obj },
     #endif
     { MP_OBJ_NEW_QSTR(MP_QSTR_log), (mp_obj_t)&mp_math_log_obj },
+    #if MICROPY_PY_MATH_SPECIAL_FUNCTIONS
     { MP_OBJ_NEW_QSTR(MP_QSTR_log2), (mp_obj_t)&mp_math_log2_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_log10), (mp_obj_t)&mp_math_log10_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_cosh), (mp_obj_t)&mp_math_cosh_obj },
@@ -206,6 +207,7 @@
     { MP_OBJ_NEW_QSTR(MP_QSTR_acosh), (mp_obj_t)&mp_math_acosh_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_asinh), (mp_obj_t)&mp_math_asinh_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_atanh), (mp_obj_t)&mp_math_atanh_obj },
+    #endif
     { MP_OBJ_NEW_QSTR(MP_QSTR_cos), (mp_obj_t)&mp_math_cos_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_sin), (mp_obj_t)&mp_math_sin_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_tan), (mp_obj_t)&mp_math_tan_obj },
diff --git a/py/qstrdefs.h b/py/qstrdefs.h
index e91cfa8..99304a9 100644
--- a/py/qstrdefs.h
+++ b/py/qstrdefs.h
@@ -370,8 +370,11 @@
 Q(sqrt)
 Q(pow)
 Q(exp)
+#if MICROPY_PY_MATH_SPECIAL_FUNCTIONS
 Q(expm1)
+#endif
 Q(log)
+#if MICROPY_PY_MATH_SPECIAL_FUNCTIONS
 Q(log2)
 Q(log10)
 Q(cosh)
@@ -380,6 +383,7 @@
 Q(acosh)
 Q(asinh)
 Q(atanh)
+#endif
 Q(cos)
 Q(sin)
 Q(tan)