QCLINUX: Revert^2 "QCLINUX: arm64: configs: qcom_defconfig: Disable NVMEM_REBOOT_MODE"

This reverts commit 00a344ea.

Reason for revert: The control of booting to different reboot modes
will be moved to psci driver and will be handled via psci_system_reset2
smc call.

Change-Id: I13a897496ada1e7362b2247c55775e395c4f30ee
Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>