1. Correcting the type of alpha, and beta values from C_type
(output type) to accumulation type.
For the downscaled LPGEMM APIs, C_type will be the downscaled
type but the required type for alpha and beta values should
be the accumulation type.
2. BF16 bench integration with the LPGEMM bench for both the BF16
(bf16bf16f32of32 and bf16bf16f32obf16) APIs
AMD-Internal: [CPUPL-2561]
Change-Id: I3a99336c743f3880be1b96605ceeeae7c3bd4797