[PATCH v2] sparc/leon: add support for partial write psr instruction

[Jose E. Marchesi]

    Thanks Jose!
    
    I do not have commit access, would you mind applying the patch for
    me?

I did some regression testing (in a S7 sparc64-linux-gnu box) for the
following targets:

SPARC_TARGETS="sparc-linux sparc-vxworks sparc64-linux
               sparc-sun-solaris2.12"

X86_TARGETS="i386-darwin i386-lynxos i586-linux i686-nacl i686-pc-beos 
             i686-pc-elf i686-pe i686-vxworks x86_64-linux x86_64-w64-mingw32
             x86_64-nacl "

All good.  I applied the patch.
Thanks!