Revert "KVM: x86: Increase the number of fixed MTRR regs to 10"

commit 0d234daf7e0a3290a3a20c8087eefbd6335a5bd4 upstream.

This reverts commit 682367c494869008eb89ef733f196e99415ae862,
which causes 32-bit SMP Windows 7 guests to panic.

SeaBIOS has a limit on the number of MTRRs that it can handle,
and this patch exceeded the limit.  Better revert it.
Thanks to Nadav Amit for debugging the cause.

Reported-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>