serial: msm_geni_serial: Disable irq only for HSUART usecase

This change restricts disabling of core interrupt only for HSUART case
from probe function. Console usecase requires irq to be in enable state
to handle RX data.

Change-Id: I244c68e8e327729734bda42aa1b90a914375e147
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>