aes-gcm: fix `P_MAX` and `A_MAX` values (#762) #129

Job	Run time
test (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	47s
test (i686-unknown-linux-gnu, 1.85.0, sudo apt update && sudo apt install gcc-multilib)	48s
test (x86_64-unknown-linux-gnu, 1.85.0)	30s
build (stable, armv7a-none-eabi)	21s
build (stable, wasm32-unknown-unknown)	23s
build (1.85.0, armv7a-none-eabi)	15s
test (x86_64-unknown-linux-gnu, stable)	21s
build (1.85.0, thumbv7em-none-eabi)	16s
build (1.85.0, wasm32-unknown-unknown)	17s
build (stable, thumbv7em-none-eabi)	13s
	4m 11s

Provide feedback