Do not support epoll mode

[squarepants0]

When I tried to emulate an epoll-mode program which is on linux-c mipsel, the qiling engine came up with this:

[!]     0x90083df4: syscall ql_syscall_epoll_create number = 0x1098(4248) not implemented
[=]     fcntl64(fd = 0x3, cmd = 0x3, arg = 0x0) = 0x2
[=]     fcntl64(fd = 0x3, cmd = 0x4, arg = 0x82) = 0x0
[!]     0x90083e6c: syscall ql_syscall_epoll_ctl number = 0x1099(4249) not implemented
[=]     rt_sigaction(signum = 0x2, act = 0x7ff3cc40, oldact = 0x9003ebc8) = 0x0
[=]     rt_sigaction(signum = 0x12, act = 0x7ff3cc40, oldact = 0x9003ebe4) = 0x0
[=]     clock_gettime(clock_id = 0x1, tp = 0x7ff3cc60) = 0x0
[Hit] waitpid
[=]     my_waitpid(pid = 0xffffffff, wstatus = 0x7ff3cc88, options = 0x1) = 0x0
[=]     clock_gettime(clock_id = 0x1, tp = 0x7ff3cc60) = 0x0
[!]     0x90083ee8: syscall ql_syscall_epoll_wait number = 0x109a(4250) not implemented

So I properly need to implement this by myself if I want to make through this

[xwings]

Please do PR once you manage to do it :)