[testlib] Add support for build both GPU dgemm+sgemm executables

[ebirn]

Motivation: We have a bunch of RTX6000 devices at our site, which have a large difference in float vs double performance. For others like V100, P100 the TF/s difference is roughly 2x.

The changes to get the sgemm executable compiled:

• template the dgemm gpu test code to allow execution of both Dgemm and Sgemm.
• the makefiles are modified to define the codepaths through defines (float or double) and produce 2 executables

Note: I was not able to test the makefile.hip , so at this point I'm just assuming it will work

Question: if this is to be accepted, should the 'dgemm' directory be renamed, along with the Dgemm base test?

[jenkins-cscs]

Can I test this patch?

[vkarak]

ok to test

[codecov-commenter]

Codecov Report

Merging #2372 (5a4d680) into master (eddf0b2) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2372   +/-   ##
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  Coverage   86.14%   86.14%           
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  Files          56       56           
  Lines       10225    10225           
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  Hits         8808     8808           
  Misses       1417     1417           

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[vkarak]

I will merge this PR as is. For the moment, I would wait for adapting the test to build both dgemm and sgemm because this tree is a bit old and uses some early practices of writing library tests. We should generally revamp the corresponding reframe test.