[M2351] Refine UART code
[M2351] Refine UART code

1. Replace SYS_ResetModule/CLK_SetModuleClock/CLK_EnableModuleClock/CLK_DisableModuleClock with TrustZone-aware versions.
2. Configure all UART to secure
3. Support asynchronous transfer
4. Remove sleep management code, which has been replaced with Sleep Manager.

kjbracey-arm/mbed,mbedmicro/mbed,mbedmicro/mbed,betzw/mbed-os,andcor02/mbed-os,betzw/mbed-os,c1728p9/mbed-os,andcor02/mbed-os,mbedmicro/mbed,andcor02/mbed-os,andcor02/mbed-os,betzw/mbed-os,c1728p9/mbed-os,c1728p9/mbed-os,kjbracey-arm/mbed,betzw/mbed-os,c1728p9/mbed-os,andcor02/mbed-os,kjbracey-arm/mbed,c1728p9/mbed-os,betzw/mbed-os,betzw/mbed-os,mbedmicro/mbed,andcor02/mbed-os,c1728p9/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed