Remove the usage of floats

[bjoernQ]

Currently we use floats in one place:

esp-hal/esp-hal-common/src/timer.rs

Lines 226 to 229 in 907d43e

	// TODO can we get this to not use doubles/floats
	let period = 1_000_000f64 / (clock.to_Hz() as f64 / divider as f64); // micros
	(micros as f64 / period) as u64

If possible we should remove that since it adds 2k of code (optimized) for ESP32-C3:

File  .text   Size                       Crate Name
0.0%  12.3% 1.2KiB           compiler_builtins compiler_builtins::float::div::__divdf3
0.0%   3.0%   292B           compiler_builtins __floatundidf
0.0%   1.6%   156B           compiler_builtins __floatunsidf
0.0%   1.4%   140B           compiler_builtins __gedf2
0.0%   1.4%   140B           compiler_builtins __gtdf2
0.0%   1.3%   130B           compiler_builtins __fixunsdfdi

[bjoernQ]

note: the upcoming LEDC implementation is currently also using floats

[jessebraham]

I did say to @JurajSadel that we can not worry about the floats right now, just for the sake of getting things completed and merged. If you have a problem with this please feel free to say so though, doesn't really make a difference to me.

[bjoernQ]

No problem with that - we can replace the floats in one go later