Implement initial support for STM32L4 (without CAN & I2S)

[tomazvidovic]

alxAdc_McuStm32 - DONE

• Style improvements
• clock init L4? - auralix/alx-202-af-10-1-auralix-c-lib#47
• renamed enum to AlxAdc_Clk_McuStm32L4_AdcClk_30MHz_Sysclk_120MHz - "Sysclk"
• merged ForceReset with STM32F4 #define

alxClk_McuStm32 - DONE

• Style improvements
• why did you turn on HSI RCC_OSCILLATORTYPE_HSI48 pri AlxClk_Ctor_McuStm32L4_Sysclk_16MHz_Pclk1Apb1_16MHz_Pclk2Apb2_16MHz_Hsi_16MHz & AlxClk_Ctor_McuStm32L4_Sysclk_120MHz_Pclk1Apb1_120MHz_Pclk2Apb2_120MHz_Hsi_16MHz
• HsiBackup was used for HSI... removed this
• Fixed namig Mhz to MHz in enum for BackuHsi for all series

alxGlobal_McuStm32xxx.h - DONE

• Style improvements

alxDac_McuStm32 - DONE

• Style improvements
• Reorganized code, implemented AlxDac_Init_Private & AlxDac_SetVoltage_V_Private
• Added for ch2 #define GetCh function
• TODO set whole structure - auralix/alx-202-af-10-1-auralix-c-lib#48

alxI2c_McuStm32 - DONE

• Style improvements

alxIoPin_McuStm32 - DONE

• Style improvements

alxIoPinIrq_McuStm32 - DONE

• Style improvements
• resolved auralix/alx-202-af-10-1-auralix-c-lib#49

alxPwm_McuStm32 - DONE

• Style improvements
• improved SIZE_OPTIMIZE system

alxRtc_McuStm32 - DONE

• Style improvements

alxSerialPort_McuStm32 - DONE

• Style improvements
• renamed to AlxSerialPort_IrqHandle
• removed AlxSerialPort_WriteMulti, renamed it to AlxSerialPort_Write

alxSpi_McuStm32 - DONE

• Style improvements

alxTrace_McuStm32 - DONE

• Style improvements
• threadSafe mutex implementation
• minor bug fix