sys/syscalls: make gettimeofday() implementation optional

[fjmolinas]

Contribution description

A follow-up to #17732 to not force 64bit on all syscalls users.

With this PR the users of ztimer64 should be limited to:

Revisited list of apps using ztimer64:

for app in examples/* tests/*; do make -C ${app} info-modules | if grep -q ztimer64; then echo ${app};fi;done

examples/ccn-lite-relay
examples/cord_ep
examples/cord_lc
examples/dtls-echo
examples/dtls-sock
examples/dtls-wolfssl
examples/gcoap_dtls
examples/gnrc_networking_mac
examples/lua_basic
examples/lua_REPL
examples/openthread
examples/posix_select
examples/wasm
tests/cpp11_condition_variable
tests/cpp11_mutex
tests/cpp11_thread
tests/driver_ltc4150
tests/driver_pir
tests/gnrc_gomach
tests/lua_loader
tests/nimble_autoconn_ccnl
tests/pkg_arduino_sdi_12
tests/pkg_flatbuffers
tests/pkg_tensorflow-lite
tests/pkg_tinydtls_sock_async
tests/pkg_wolfcrypt-ed25519-verify
tests/pkg_wolfssl
tests/posix_semaphore
tests/pthread
tests/pthread_barrier
tests/pthread_cleanup
tests/pthread_condition_variable
tests/pthread_cooperation
tests/pthread_flood
tests/pthread_rwlock
tests/pthread_tls
tests/saul_drivers
tests/sema
tests/sntp
tests/sys_fido2_ctap
tests/unittests
tests/ztimer64_msg

Testing procedure

Green Murdock, although should probably wait for #17721 or cherry-pick f7f7a93 to test for missing dependencies.

Issues/PRs references

Follow up to #17732
Related to #17721 and #17365

[fjmolinas]

I think I'll wait for #17719 and then rebase on #17721.

[fjmolinas]

@kaspar030 @kfessel all green here, would be good to get this in to reduce ztimer64 users!

[kfessel]

I think the pseudo module could have a shorter name. libc_gettimeofday

[fjmolinas]

@kfessel changes addressed!

[kfessel]

two small nitpicks in Makefile.dep other than that this is good to go

u can skip the murdock

[kfessel]

green murdock and good change

[benpicco]

This breaks esp32 😢
RIOT-OS/Release-Specs#247 (comment)