x86 UEFI: Fix broken build for UEFI

UEFI loads EFI applications to dynamic runtime addresses, so it requires
all applications to be compiled as PIC (position independent code).

The new introduced single-step #DB tests series bring some compile time
absolute address, fixed it with RIP relative address.

Fixes: 9734b423 ("x86/debug: Add framework for single-step #DB tests")
Fixes: 6bfb9572 ("x86/debug: Test IN instead of RDMSR for single-step #DB emulation test")
Fixes: bc0dd8bd ("x86/debug: Add single-step #DB + STI/MOVSS blocking tests")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20220210092044.18808-1-zhenzhong.duan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>