arch/arm/src/tiva: Add GPIO IRQ stubs for clean compile
arch/arm/src/tiva/cc13xx: Add build framework for CC13xx GPIO interrupts. Change prototypes of some GPIO IRQ interfaces so that the function prototype is common between LM3S, LM4F, TM4C, and CC13xx.
arch/arm/src/tiva: Add CC13xx GPIO driver plus various fixes for clean compilation.
arch/arm/src/tiva/ and configs/launchxl-cc1312r1: Make type of the GPIO pin configuration an abstract type so that CC13xx MCUs can share the same GPIO function prototypes and usage model.