control/server.py: support --cpumask=0xF

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control/server.py: support --cpumask=0xF

• SPDK CPU auto detect code has issues #866

The spdk argument defined here - https://github.com/ceph/spdk/blob/0d9430fab9b368761b13dc73a65b0ed13d6c6bc6/lib/event/app.c#L97-L98

The getopt_long option expects a required argument (indicated by required_argument).
The option can be passed in two forms:

• Long option: --cpumask 0xF or --cpumask=0xF
• Short option: -m 0xF

A sample test code to test valid/parsable command line variants for -m//--cpumask:

#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>

#define CPUMASK_OPT_IDX 'm'

int main(int argc, char *argv[]) {
    int option;
    char *cpumask_value = NULL;

    // Define the long options
    static struct option long_options[] = {
        {"cpumask", required_argument, NULL, CPUMASK_OPT_IDX},
        {0, 0, 0, 0}
    };

    // Parse the command-line options
    while ((option = getopt_long(argc, argv, "m:", long_options, NULL)) != -1) {
        switch (option) {
            case CPUMASK_OPT_IDX:
                cpumask_value = optarg;  // Get the cpumask argument value
                printf("cpumask option value: %s\n", cpumask_value);
                break;
            case '?':  // Invalid option
                printf("Unknown option!\n");
                return 1;
            default:
                printf("Usage: %s -m <value> or --cpumask=<value>\n", argv[0]);
                return 1;
        }
    }

    if (cpumask_value) {
        printf("Successfully parsed cpumask: %s\n", cpumask_value);
    } else {
        printf("cpumask argument was not provided.\n");
    }

    return 0;
}