ohos: fix build with llvm/clang 22 about missing initializer

src/plugins/position/ohos/qohosgeopositioninfosource.cpp:147:21: error: missing field 'optEventSourceAliveCheckFunc' initializer [-Werror,-Wmissing-designated-field-initializers]
  147 |                     }));
      |                     ^

Pick-to: 6.12
Change-Id: I3396732332f7ed7ec64c050ea3e075e24fd064c7
Reviewed-by: SanthoshKumar Selvaraj <santhosh.kumar.selvaraj@qt.io>