AP_NavEKF2: stop including AP_DAL.h in header

[peterbarker]

it's not needed and will slow compilation down

Board                    AP_Periph  blimp  bootloader  copter  heli  iofirmware  plane  rover  sub
CubeOrange-periph-heavy  *                                                 
Durandal                            *      *           *       *                 *      *      *
Hitec-Airspeed           *                                                 
KakuteH7-bdshot                     *      *           *       *                 *      *      *
MatekF405                           *      *           *       *                 *      *      *
Pixhawk1-1M-bdshot                  *                  *       *                 *      *      *
f103-QiotekPeriph        *                                                 
f303-Universal           *                                                 
iomcu                                                                *     
revo-mini                           *      *           *       *                 *      *      *
skyviper-v2450                                         *                   

[tridge]

I think we should add a ekf2 enabled build on a ChibiOS board (eg. CubeOrange) in build_ci.sh

[tridge]

can be merged when we also have a CI check for build with EK2+EK3 on a ChibiOS boards

[peterbarker]

Added the CI check for EKF2. Now saves a few bytes (optimisation changes):

Board                    AP_Periph  blimp  bootloader  copter  heli  iofirmware  plane  rover  sub
CubeOrange-periph-heavy  0                                                                     
Durandal                            -8     *           -16     -16               -16    -16    -16
Hitec-Airspeed           *                                                                     
KakuteH7-bdshot                     -72    *           -88     -88               -88    -80    -88
MatekF405                           -56    *           -64     -64               -64    -64    -64
Pixhawk1-1M-bdshot                  -80                -88     -88               -96    -88    -96
f103-QiotekPeriph        *                                                                     
f303-Universal           *                                                                     
iomcu                                                                *                         
revo-mini                           -56    *           -64     -64               -64    -64    -64
skyviper-v2450                                         -64