ANDROID: KVM: arm64: Allocate host fp state at pkvm init rather than per cpu

Subsequent patches will augment this state to allocate space for
tracking the host sve state. SVE state size is not static, and
there isn't support for dynamic per_cpu allocation in hyp.

This is done as a first step in allowing us to allocate SVE state
under the same umbrella.

Signed-off-by: Fuad Tabba <tabba@google.com>

Bug: 267291591
Change-Id: I0902623a5ab81a80105f5b00a26765d257bc1ceb