hw/mcu/stm/stm32_common: Add include for os_cputime.h (#2318)
hw/mcu/stm/stm32_common: Add include for os_cputime.h (#2318)

The stm32_periph.c file may not include os_cputime.h if certain
syscfg values are not set. This explicitly include os_cputime.h
if OS_CPUTIME_TIMER_NUM is >= 0.

Fix parentheses.
mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core