Add initial support for Gaisler-BCC with Sparc

[LinuxJedi]

Description

Slight modifications and documentation to get wolfSSL working with Gaisler Sparc CPUs and their cross-compilers.

Testing

Using TSIM3 LEON3 evaluation version (https://www.gaisler.com/index.php/downloads/simulators).

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[douzzer]

retest this please

[douzzer]

from PRB-multi-test-script:

[check-source-text] [2 of 7] [wolfssl]
    autogen.sh wolfssl...   real 0m14.913s  user 0m8.756s  sys 0m0.214s
    configure...   real 0m21.143s  user 0m9.405s  sys 0m2.425s
unrecognized macros used:
__sparc
add well-formed but unknown macros to /tmp/workspace/PRB-multi-test-script/wolfssl/.wolfssl_known_macro_extras.

(it means .wolfssl_known_macro_extras at the top of the repo.)

There's also an error in PRB-fips-read-config but I think it's a false positive.

[LinuxJedi]

Dang, when it kept failing I thought that might be the case, but I didn't see it in the Jenkins output. I'll fix ASAP.

[LinuxJedi]

@douzzer I fixed that problem. Any idea why Jenkins is still failing? I don't see it in the log.

[douzzer]

retest this please (PRB-140-3 -tests 140-3-known-tests/AES-GMAC_474643.json "DRBG Continuous Test FIPS error")

[douzzer]

By the way, glibc no longer has support for pre-v8 sparc, and trying to build a toolchain for sparc-unknown-linux-gnu (to get a 32 bit sparc runtime) makes it think pre-v8 is targeted, so the build craps out.

TL;DR: Currently we have sparc64 testing in the nightly (just basic testsuite.test), but not sparc32.

P.s. interestingly, on sparc64, we have to disable sakke to get it to pass, otherwise SEGV. Before this PR, also had to force on WOLFSSL_SP_INT_DIGIT_ALIGN.