dma: Provide generic look-up functions for 'width' and 'burst' register entries

Most controllers (including the QMSI driver currently supported in
Zephyr) use generic register values when configuration 'width' and
'burst'.  Thus, let's provide a generic look-up to save every
controller requiring their own one.  This should reduce the chance
of needless code duplication.

Change-Id: I49d749775bbf23f4bdcce4fa39685681fdcf6e1e
Signed-off-by: Lee Jones <lee.jones@linaro.org>
1 file changed