using only px4_getopt() and never the unsafe getopt()

using only <px4_getopt.h> as include, cleanup related includes
added check that all the option are valid (myoptind >= argc). if there are invalid options on some script that might now lead not to run commands

src/drivers/pca9685/pca9685.cpp

@@ -61,6 +61,7 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <math.h>
+#include <px4_getopt.h>
 
 #include <nuttx/wqueue.h>
 #include <nuttx/clock.h>
@@ -531,10 +532,13 @@ pca9685_main(int argc, char *argv[])
 	int i2cdevice = -1;
 	int i2caddr = ADDR; // 7bit
 
+	int myoptind = 1;
 	int ch;
+	const char *myoptarg = nullptr;
+
 
 	// jump over start/off/etc and look at options first
-	while ((ch = getopt(argc, argv, "a:b:")) != EOF) {
+	while ((ch = px4_getopt(argc, argv, "a:b:", &myoptind, &myoptarg)) != EOF) {
 		switch (ch) {
 		case 'a':
 			i2caddr = strtol(optarg, NULL, 0);
@@ -550,12 +554,12 @@ pca9685_main(int argc, char *argv[])
 		}
 	}
 
-	if (optind >= argc) {
+	if (myoptind >= argc) {
 		pca9685_usage();
-		exit(1);
+		exit(0);
 	}
 
-	const char *verb = argv[optind];
+	const char *verb = argv[myoptind];
 
 	int fd;
 	int ret;