crypto/ccp: Update HV_FIXED page states to allow freeing of memory

crypto/ccp: Update HV_FIXED page states to allow freeing of memory

After SNP is disabled, any pages allocated as HV_FIXED can now be freed.
Update the page state of these pages and the snp_leak_hv_fixed_pages()
function to free pages on SNP_SHUTDOWN.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://patch.msgid.link/20260324161301.1353976-8-tycho@kernel.org