perf tools mips: Fix mips syscall generation

JIRA: https://issues.redhat.com/browse/RHEL-77936

upstream
========
commit b1bb6fc
Author: Charlie Jenkins <[email protected]>
Date: Fri Jan 10 11:22:51 2025 -0800

description
===========
The mips syscall generation was still based on the old method. Delete
the Makefile since it is no longer needed with the new method of
generation.

    Reported-by: Arnaldo Carvalho de Melo <[email protected]>
Fixes: 619ffe6 ("perf tools mips: Use generic syscall scripts")
    Signed-off-by: Charlie Jenkins <[email protected]>
    Cc: Adrian Hunter <[email protected]>
    Cc: Alexander Shishkin <[email protected]>
    Cc: Ian Rogers <[email protected]>
    Cc: Ingo Molnar <[email protected]>
    Cc: Jiri Olsa <[email protected]>
    Cc: Mark Rutland <[email protected]>
    Cc: Namhyung Kim <[email protected]>
    Cc: Peter Zijlstra <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]
    Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Signed-off-by: Michael Petlan <[email protected]>

Author: rfmvh