Make sure first motorCount outputs get assigned to motor on MR

[mluessi]

Updated version of #7350. This makes sure that the first N outputs get assigned to a motor on multirotor. Unlike the previous PR, it modifies the timer hardware table (like timerHardwareOverride does), so the output mapping is also correctly displayed in the configurator.

To illustrate what this does, assume we have the timer hardware list below. Without this change, it was not possible to configure and X8 with 2 additional servos, as S7 and S8 would get assigned to servos first and S9 and S10 don't support motor output. With this change, S1 to S8 will be motors and S9 and S10 servos. Similarly, on a hex with 2 servos, S1 to S6 will be motors and S7 and S8 servos.

DEF_TIM(TIM2,  CH1, PA0,   TIM_USE_MC_MOTOR | TIM_USE_FW_MOTOR, 0,  0), // S1
DEF_TIM(TIM3,  CH2, PB5,   TIM_USE_MC_MOTOR | TIM_USE_FW_MOTOR, 0,  1), // S2
DEF_TIM(TIM4,  CH1, PD12,  TIM_USE_MC_MOTOR | TIM_USE_FW_SERVO, 0,  2), // S3
DEF_TIM(TIM4,  CH2, PD13,  TIM_USE_MC_MOTOR | TIM_USE_FW_SERVO, 0,  3), // S4

DEF_TIM(TIM8,  CH4, PC9,   TIM_USE_MC_MOTOR | TIM_USE_FW_SERVO, 0,  4), // S5
DEF_TIM(TIM8,  CH3, PC8,   TIM_USE_MC_MOTOR | TIM_USE_FW_SERVO, 0,  5), // S6
DEF_TIM(TIM1,  CH3, PE13,  TIM_USE_MC_MOTOR | TIM_USE_FW_SERVO | TIM_USE_MC_SERVO, 0,  6), // S7
DEF_TIM(TIM1,  CH2, PE11,  TIM_USE_MC_MOTOR | TIM_USE_FW_SERVO | TIM_USE_MC_SERVO, 0,  7), // S8

DEF_TIM(TIM15, CH1, PA2,   TIM_USE_FW_SERVO | TIM_USE_MC_SERVO, 0,  0), // S9
DEF_TIM(TIM15, CH2, PA3,   TIM_USE_FW_SERVO | TIM_USE_MC_SERVO, 0,  0), // S10