sysctl: add cold_boot sysctl entry

Add a cold_boot parameter which supplements the
boot_reason sysctl entry with information about
whether the system was booted from cold or warm state.

/proc/sys/kernel/cold_boot entry is updated with 1 or 0 when
system was booted from cold or warm boot state respecitively.

CRs-Fixed: 461256
Change-Id: I2bc5d80c8f26eb9e9dbb4b34960d991a51a224e4
Signed-off-by: David Keitel <dkeitel@codeaurora.org>
platform/msm: qpnp-power-on: Implement cold_boot sysctl parameter

Update the cold_boot sysctl parameter by using
qpnp_pon_is_warm_reset API. cold_boot sysctrl
is updated with 1 or 0 when system was booted from
cold or warm boot states respectively.

CRs-Fixed: 461256
Change-Id: I4bb87602f76526b3e67a6466044e77fb1d823b29
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>