TCSR_BOOT_MISC_REG bits are not properly managed
for DLOAD implementation. Modify only necessary
bits to enable availability for new feature
implementations using TCSR_BOOT_MISC_REG.
Change-Id: I888a1bf6ce3654b0453c9ec2f87b4d5ff2a20de0
Signed-off-by: Gokul Sriram Palanisamy <quic_gokulsri@quicinc.com>