Hi Aamir,
try to update all BIOS and firmware prior to installing VMWare ESXi.
I think IBM/Lenovo even provides customized versions of ESXi which might help in that case, a quick search brought up this for example: Lenovo Custom Image for ESXi 5.5.0 Update 2 - BladeCenter, Flex System, Lenovo x86 servers, System x
cykVM