Enabling 8MHz clock source

[solidsnack]

It looks like this the code is implemented but is private?

esp-hal/esp-hal-common/src/rtc_cntl/mod.rs

Line 281 in d89bd54

fn enable_8m(clk_8m_en: bool, d256_en: bool) {

It's kind of interesting that the Rust library can actually enable and disable it dynamically, whereas for C it is a build configuration option.