Try both wget and curl to download cxl.h
Try both wget and curl to download cxl.h

This tests which of wget and curl is installed on the build host and
tries to use the appropriate one to download the cxl.h file if it is not
up to date.

Changed the wget command line from before to use -O to overwrite the
existing file.

ibm-capi/libcxl,vaibhav92/libcxl,vaibhav92/libcxl,ibm-capi/libcxl