Fix the typo in the Makefrag for the reference to 2-stage-translation.S

[PorterLu]

I want to test the stage-2 tests in the riscv-tests The error message is as follows:

make[1]: *** No rule to make target 'hypervisor/2-stage-translation.S', needed by 'hypervisor-p-2-stage-translation'.  Stop.

After correcting the name 2-stage-translation in isa/hypervisor/Makefrag, everything is working well fine for me.

riscv64-unknown-elf-gcc -march=rv64gh -mabi=lp64 -static -mcmodel=medany -fvisibility=hidden -nostdlib -nostartfiles -I/home/porterlu/tmp/riscv-tests/isa/../env/p -I/home/porterlu/tmp/riscv-tests/isa/macros/scalar -T/home/porterlu/tmp/riscv-tests/isa/../env/p/link.ld hypervisor/2-stage_translation.S -o hypervisor-p-2-stage_translation

[heiyuen1999]

Thank you for catching that typo. I'm sorry for my carelessness.