Omit needless rijndael dependencies.

Make crypto/rijindael optional again as cprng_strong does no longer
depend on it. Dependency is explicitly declared in files.foo if a
component requires it.

branches: 1.4.6;
make this compile again:
- remove unused config attributes
- rename a local variable to avoid a name conflict

branches: 1.3.2; 1.3.18; 1.3.22;
add new cryptographic accelerator driver 'mvxpsec.'

this driver controls CESA unit as same as mvcesa, but uses DMA engines and
does CBC operations, HMAC operations by hardware. about 2 kbytes of data
are processed at one. supported algorithms are:

- DES-CBC, 3DES-CBC, AES-CBC
- HMAC-SHA1, HMAC-MD5

non-CBC algorithm such as AES-GCM is not supported by CESA's acceleration
engine. mvcesa is still useful to implement such algorithms as combination of
accelerated block cipher and software chaining.

separate buffer management codes 'mvxpbm.c' from if_mvxpe.c.

the buffer management(ex. fill the rx descriptors/buffers) is done by H/W in
ARMADA XP/380, and is done by S/W in ARMADA 370. the H/W BM support is not yet
implemented, so all devices use the S/W management mode at this time.

move Marvell ARMADA SoC's device driver definitions from arm/marvell
to dev/marvell.