esp.c: remove MacOS TI workaround that pads FIFO transfers to ESP_FIFO_SZ

esp.c: remove MacOS TI workaround that pads FIFO transfers to ESP_FIFO_SZ

This workaround is no longer required with the current code and so can be
removed.

[Note: whilst MacOS itself can boot correctly, removing this hack prevents
a bootable EMILE CDROM from working. This is caused by a separate bug which
will be fixed by a subsequent patch]

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20240112125420.514425-17-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>