mhi: core: avoid memset of BHIE registers

Current logic does memset for a range of BHIE
registers of endpoint device. Few EP devices has
undefined regsiters in this range and upon Host
writing to those registers causing unnecessary
interrupts to device. So, avoid doing memset
to BHIE registers.

Change-Id: Ie9261621f62776a732394635b7dbfa42ab5487dc
Signed-off-by: Rama Krishna Phani A <rphani@codeaurora.org>