Added -rpath to LDFLAGS in the gdal build

[jgallagher59701]

No description provided.

[jgallagher59701]

On the M4, without this change gdalinfo, a program used for some tests, does not run correctly and three tests that should pass fail. With this change, all tests pass:
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bes 3.21.1 test suite: bes/modules/gdal_module/tests testsuite.

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5: gdal/cea.tif.r1.bescmd ok
9: gdal/UTM2GTIF.TIF.dds.bescmd ok
8: gdal/UTM2GTIF.TIF.das.bescmd ok
2: gdal/cea.tif.1.bescmd ok
1: gdal/cea.tif.0.bescmd ok
3: gdal/cea.tif.2.bescmd ok
6: gdal/cea.tif.dmr.bescmd ok
4: gdal/cea.tif.3.bescmd ok
11: gdal/UTM2GTIF.TIF.dmr.bescmd ok
14: gdal/Atlantic.wind.grb.dds.bescmd ok
13: gdal/Atlantic.wind.grb.das.bescmd ok
16: gdal/Atlantic.wind.grb.dmr.bescmd ok
7: gdal/cea.tif.dap.bescmd ok
10: gdal/UTM2GTIF.TIF.dods.bescmd ok
18: gdal/cea.tif.function.ddx.bescmd ok
19: gdal/cea.tif.function.dods.bescmd ok
20: gdal/coads_climatology.nc.0.bescmd ok
21: gdal/coads_climatology.nc.1.bescmd ok
22: gdal/coads_climatology.nc.1.err.bescmd ok
15: gdal/Atlantic.wind.grb.dods.bescmd ok
23: gdal/function_result_unwrap_tif.bescmd ok
12: gdal/UTM2GTIF.TIF.dap.bescmd ok
17: gdal/Atlantic.wind.grb.dap.bescmd ok
`