Fix QNearFieldTarget::AccessMethods flags definition

Currently QNearFieldTarget::AccessMethod enums are defined so that it's not possible to OR them together.

Targets can provide for example NDEF access and tag specific access and API should allow that.

AccessMethod enum could be updated e.g. to

enum AccessMethod {
    NdefAccess = 0x1,
    TagTypeSpecificAccess = 0x2,
    LlcpAccess = 0x4
};

For additional info, see QTMOBILITY-2024.