fix: remove Host reads and write miss tests

[anandaravuri]

• Host reads and write miss tests are same as FPGA reads and write miss, so remove from CXL host exerciser.
• Changes Host read cache hit opcode to RD_LINE_I

[coveralls]

Pull Request Test Coverage Report for Build 7279314078

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.4%) to 66.936%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
samples/cxl_host_exerciser/cxl_he_cache_cmd.h	0	1	0.0%
<!--	Total:	0	1	0.0%	-->

Totals
Change from base Build 7252306388:	0.4%
Covered Lines:	15756
Relevant Lines:	23539

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💛 - Coveralls