rsdp,acpi: update crates to 2021 edition

`aml` should also be moved to the 2021 edition at some point

Cargo.toml

@@ -1,2 +1,3 @@
 [workspace]
 members = ["rsdp", "acpi", "aml", "acpi-dumper", "aml_tester"]
+resolver = "2"

acpi/Cargo.toml

@@ -7,7 +7,7 @@ description = "Library for parsing ACPI tables"
 categories = ["hardware-support", "no-std"]
 readme = "../README.md"
 license = "MIT/Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 bit_field = "0.10.2"

rsdp/Cargo.toml

@@ -7,7 +7,7 @@ description = "Zero-allocation library for locating and parsing the RSDP, the fi
 categories = ["hardware-support", "no-std"]
 readme = "../README.md"
 license = "MIT/Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [dependencies]
 log = "0.4"