This fixes an issue originally introduced with the BGEMM kernel.
I've updated the tests to run with `beta=1.0` so as to test loading and
updating from C.
Alongside this, the tests now return sensible return values to reduce
the risk of them being ignored.
Also fixed a bug in `generic/gemv_t.c` resulting in weird outputs for
`bgemv`.
- Adds bgemv T based off of sbgemv T kernel
- Adds bgemv N which is slightly alterated to not use Y as an
accumulator due to the output being bf16 which results in loss of
precision
- Enables BGEMM_GEMV_FORWARD to proxy BGEMM to BGEMV with new kernels
- Sets up all the various entrypoints for `bgemv`
- Adds `bscal` for use in the `bgemv` interface
- Adds test cases for comparing `sgemv` and `bgemv`
- Adds generic kernels for `bgemv_n` and `bgemv_t` which are accurate
enough to pass above tests
Chris Sidebottom