src/platforms: move all headers to platforms/common/include/px4_platform_common

and remove the px4_ prefix, except for px4_config.h.

command to update includes:
for k in app.h atomic.h cli.h console_buffer.h defines.h getopt.h i2c.h init.h log.h micro_hal.h module.h module_params.h param.h param_macros.h posix.h sem.h sem.hpp shmem.h shutdown.h tasks.h time.h workqueue.h; do for i in $(grep -rl 'include <px4_'$k src platforms boards); do sed -i 's/#include <px4_'$k'/#include <px4_platform_common\/'$k/ $i; done; done
for in $(grep -rl 'include <px4_config.h' src platforms boards); do sed -i 's/#include <px4_config.h/#include <px4_platform_common\/px4_config.h'/ $i; done

Transitional headers for submodules are added (px4_{defines,log,time}.h)

platforms/common/include/px4_platform_common/time.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <time.h>
+#include <pthread.h>
+
+#if defined(__PX4_APPLE_LEGACY)
+#define clockid_t int
+#endif
+
+#if defined(__PX4_POSIX) || defined(__PX4_QURT)
+__BEGIN_DECLS
+__EXPORT int px4_clock_gettime(clockid_t clk_id, struct timespec *tp);
+__END_DECLS
+#else
+#define px4_clock_gettime system_clock_gettime
+#endif
+
+#if defined(ENABLE_LOCKSTEP_SCHEDULER)
+
+__BEGIN_DECLS
+__EXPORT int px4_clock_settime(clockid_t clk_id, const struct timespec *tp);
+
+__EXPORT int px4_usleep(useconds_t usec);
+__EXPORT unsigned int px4_sleep(unsigned int seconds);
+__EXPORT int px4_pthread_cond_timedwait(pthread_cond_t *cond,
+					pthread_mutex_t *mutex,
+					const struct timespec *abstime);
+__END_DECLS
+
+#else
+
+#define px4_clock_settime system_clock_settime
+#define px4_usleep system_usleep
+#define px4_sleep system_sleep
+#define px4_pthread_cond_timedwait system_pthread_cond_timedwait
+
+#endif