I noticed support for powerpc in openssl in the below link: https://github.com/openssl/openssl/blob/master/crypto/sha/asm/keccak1600-ppc64.pl
However, the hardware I am using , the source of that are compiled with -mcpu=440fp compiler option.
The doubt is will the OPENSSL assembly(above) be compatible with my hardware if integrated?
It will not work.
The assembly you linked is for PPC64, whereas your core only supports 32-bit PowerPC with ISA level 2.03.
When in doubt, try to assemble the code with option -mcpu=440fp. If it assembles, it'll most likely run. If not, it will not.