MIPS: KVM: Remove outdated README

This file was created long ago and information inside is
obviously outdated.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20200710063047.154611-4-jiaxun.yang@flygoat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>