Add support for CMake generators when installing dependencies.

[amd-jmacaran]

• cget tool supports -G parameter to specify generator. Reference
• This code change provides capability to leverage that support and let user pick a generator with install_deps.cmake, limiting to Ninja or Unix Makefiles at the moment.
• Example Usage: cmake -P install_deps.cmake --prefix $(HOME))/miopen-deps --generator Ninja
• Trial run on Azure VM with 64 cores cut down execution time of this script by a few minutes. Pipeline Log

[DrizztDoUrden]

Suggested change

	if(DEFINED GENERATOR)
	cget(install -G ${GENERATOR} -U ROCm/rocm-recipes@92c6695449c85887962f45509b376f2eb0d284f7)
	cget(install -G ${GENERATOR} -U -f requirements.txt)
	else()
	cget(install -U ROCm/rocm-recipes@92c6695449c85887962f45509b376f2eb0d284f7)
	cget(install -U -f requirements.txt)
	endif()
	cget(install ${CGET_EXTRA_OPTIONS} -U ROCm/rocm-recipes@92c6695449c85887962f45509b376f2eb0d284f7)
	cget(install ${CGET_EXTRA_OPTIONS} -U -f requirements.txt)

I suggest instead of having a dedicated generator value having an CGET_EXTRA_OPTIONS cmake variable. That would allow adding support for more options when needed without making a huge if-else tree or rewriting.