Some timer #define statements are missing for MAX32650

[alperenguclu]

Some timer #define statements are missing for MAX32650, we have some code for MAX32690 we ported to MAX32650, and we observed that it is missing at the header file max32650.h. It is also missing for some other micros and will be nice to add all.

#define SEC(s) (((uint32_t)s) * 1000000UL)
#define MSEC(ms) (ms * 1000UL)
#define USEC(us) (us)