i'm by no means an expert on the configuration of this but the first thind i notice is at the very top in the 'Configure Command' is has this...
'./configure' '--with-ibm-db2' '--with-config-file-path=/QOpenSys/php/etc' '--prefix=/QOpenSys/php/' '--enable-force-cgi-redirect' '--without-mysql' '--enable-inline-optimization' '--disable-debug' '--with-zlib' '--build=powerpc-ibm-aix4.3.3.0' '--host=powerpc-ibm-aix4.3.3.0'
And in that quote you will notice '--without-mysql' - i guess this instruction needs removed.