cmd: replace efi_create_handle/add_protocol with InstallMultipleProtocol

In general handles should only be deleted if the last remaining protocol
is removed.  Instead of explicitly calling
efi_create_handle -> efi_add_protocol -> efi_delete_handle which blindly
removes all protocols from a handle before removing it,  use
InstallMultiple/UninstallMultiple which adheres to the EFI spec and only
deletes a handle if there are no additional protocols present

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>