crypto: omap-aes: Add macro to calculate how much an SG is walked

Add a useful macro that is used through out the code for a common
pattern of calculated how much an SG list has been walked. Improves
readability and avoids checkpatch errors.

Signed-off-by: Joel Fernandes <joelf@ti.com>
crypto: omap-aes: Add IRQ handler for PIO mode

We add an IRQ handler that implements a state-machine for PIO-mode
and data structures for walking the scatter-gather list. The IRQ handler
is called in succession both when data is available to read or next
data can be sent for processing. This process continues till the entire
in/out SG lists have been walked. Once the SG-list has been completely
walked, the IRQ handler schedules the done_task tasklet.

Signed-off-by: Joel Fernandes <joelf@ti.com>
crypto: omap-aes: Initialize data and triggers for PIO mode

We initialize the scatter gather walk lists needed for PIO mode
and avoid all DMA paths such as mapping/unmapping buffers by
checking for the pio_only flag.

Signed-off-by: Joel Fernandes <joelf@ti.com>
crypto: omap-aes: Setup for PIO mode in probe function

In cases where requesting for DMA channels fails for some reason, or channel
numbers are not provided in DT or platform data, we switch to PIO-only mode
provided interrupt information and interrupt register offsets are provided in
DT and platform data. All dma-only paths are avoided in this mode.

Signed-off-by: Joel Fernandes <joelf@ti.com>
crypto: omap-des: Add omap-des driver

Reused from omap-aes with constants and functions renamed, register
offsets adjusted and other fixes. Includes the DMA rewrite and all
PIO mode improvements made to the omap-aes driver.

Among others, changes made for adjusting key size, block size, removing
non-existent encryption modes and added support for OMAP4 platform data
and offsets.

Signed-off-by: Joel Fernandes <joelf@ti.com>
crypto: omap-des: Add config and build options

Add config and build options for the newly added omap-des driver.

Signed-off-by: Joel Fernandes <joelf@ti.com>