The vcu disable bit in efuse ipdisable register is valid
only if PL powered up so, consider PL powerup status for
determing EG/EV part. If PL is not powered up, display
EG/EV as a part of string. The PL powerup status will
be filled by pmufw based on PL PROGB status in the
9th bit of version field.This patch also used IPI
to get this info from pmufw instead of directly accessing
the registers. Accessing this info from pmufw using
IPI fixes the issue of PMUFW access denied error for
reading IPDISABLE register.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>