ardupilotwaf: add -fno-math-errno to ChibiOS boards

[tpwrules]

Allows better use of math instructions as opposed to calling library functions to implement math like sqrt. This saves flash and increases speed. ArduPilot does not use EDOM or ERANGE anyway.

Might cause issues with malloc errno:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88576 but ArduPilot does not check for ENOMEM or use errno much anyway.

Board                    AP_Periph  blimp  bootloader  copter  heli   iofirmware  plane  rover  sub
CubeOrange-periph-heavy  -400              *
Durandal                            -352   *           -1216   -1000              -1344  -744   -640
Hitec-Airspeed           *                 *
KakuteH7-bdshot                     368    *           0       208                216    352    400
MatekF405                           16     *           -120    -24                -112   96     0
Pixhawk1-1M-bdshot                  0                  32      -48                -48    32     -16
f103-QiotekPeriph        *                 *
f303-Universal           -160              *
iomcu                                                                 *
revo-mini                           8      *           -120    -32                -120   88     0
skyviper-v2450                                         -168

Seems this results in really bad inlining decisions on -Os targets. I have a followup but am curious if this is a desired flag.

Tested on CubeOrange using scripting aerobatics in SITL on HW.