x86/efi: Remove unused efi_call* macros

Complement commit 62fa6e69 ("x86/efi: Delete most of the efi_call*
macros") and delete the stub macros for the !CONFIG_EFI case, too. In
fact, there are no EFI calls in this case so we don't need a dummy for
efi_call() even.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>