OvmfPkg/RiscVVirt/README: document direct kernel boot #198

Job	Run time
Analyze (ArmPkg, IA32,X64)	11m 51s
Analyze (CryptoPkg, IA32)	24m 33s
Analyze (CryptoPkg, X64)	27m 15s
Analyze (DynamicTablesPkg, IA32,X64)	11m 0s
Analyze (FatPkg, IA32,X64)	18m 48s
Analyze (FmpDevicePkg, IA32,X64)	19m 31s
Analyze (IntelFsp2Pkg, IA32,X64)	13m 28s
Analyze (IntelFsp2WrapperPkg, IA32,X64)	13m 21s
Analyze (MdeModulePkg, IA32)	24m 57s
Analyze (MdeModulePkg, X64)	26m 30s
Analyze (MdePkg, IA32,X64)	19m 20s
Analyze (PcAtChipsetPkg, IA32,X64)	15m 19s
Analyze (PrmPkg, IA32,X64)	17m 58s
Analyze (SecurityPkg, IA32,X64)	19m 45s
Analyze (ShellPkg, IA32,X64)	20m 46s
Analyze (SourceLevelDebugPkg, IA32,X64)	12m 47s
Analyze (StandaloneMmPkg, IA32,X64)	17m 35s
Analyze (UefiCpuPkg, IA32,X64)	22m 32s
Analyze (UnitTestFrameworkPkg, IA32,X64)	19m 36s
	5h 56m 52s

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