unix/mpconfigport: Make MICROPY_EVENT_POLL_HOOK call usleep directly.

So that MICROPY_EVENT_POLL_HOOK can be used without including py/mphal.h.

Signed-off-by: Damien George <damien@micropython.org>

ports/unix/mpconfigport.h

@@ -328,7 +328,7 @@ static inline unsigned long mp_urandom_seed_init(void) {
     do { \
         extern void mp_handle_pending(bool); \
         mp_handle_pending(true); \
-        mp_hal_delay_us(500); \
+        usleep(500); /* equivalent to mp_hal_delay_us(500) */ \
     } while (0);
 
 #include <sched.h>

ports/unix/unix_mphal.c

@@ -233,7 +233,7 @@ void mp_hal_delay_ms(mp_uint_t ms) {
     #ifdef MICROPY_EVENT_POLL_HOOK
     mp_uint_t start = mp_hal_ticks_ms();
     while (mp_hal_ticks_ms() - start < ms) {
-        // MICROPY_EVENT_POLL_HOOK does mp_hal_delay_us(500) (i.e. usleep(500)).
+        // MICROPY_EVENT_POLL_HOOK does usleep(500).
         MICROPY_EVENT_POLL_HOOK
     }
     #else