ANDROID: arm64: Fixes ioremap for legacy host

In case of a legacy host (i.e. without KVM_FUNC_HAS_RANGE) mmio guard
works on a per-page (i.e. hyp PAGE_SIZE) basis. Some mismatch between
what's bytes and what is nr_granules lead to a failure in a such
configuration. Fix it.

Bug: 278749606
Bug: 243642516
Fixes: 4a93f65b ("ANDROID: arm64: ioremap/iounmap use range for MMIO guard hypercalls")
Change-Id: If8217dcb442bad359f949ac7adab80e06a509535
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>