fix(acpi): Fixed how kepler searches for ACPI in hwmon

[vimalk78]

ACPI power meter in hwmon need not always be present in "/sys/class/hwmon/hwmon2"

This commit fixes this problem by

• looking inside each folder in "/sys/class/hwmon"
• improving the method to detect presece of acpi power meter. (this method is inspired from lm-sensors project)

[vimalk78]

Cc: @rootfs @marceloamaral

[sthaha]

@vimalk78 thoughts on closing this PR?

[vimalk78]

@vimalk78 thoughts on closing this PR?

if community thinks this is not needed, i can close it