can: mcp25xxfd: optimize TEF reads reading multiple TEFs in one go

To reduce the amount of spi_messages send this patch optimizes the
read TEF so that multiple TEFs are read together.

So to read all of those 100000 TEF frames to read we formerly have
scheduled 100000 spi_messages.
While with this patch we have only scheduled 44691 spi_messages, so
only 44.6% of the former value.
This also means we have not been transferring 110618 (=2*30349+2*2*12480)
unnecessary command bytes over the SPI bus.

Change-Id: I8938aba258d209a0d3879530732cd60e33d2b66e
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Git-commit: 65c507a8
Git-repo: https://github.com/msperl/linux-rpi/releases/tag/mcp25xxfd-V8.2


Signed-off-by: Ke Du <quic_kedu@quicinc.com>