drivers: Remove unnecessary CONFIG_SYS_POWER_DEEP_SLEEP

This commit removes unnecessary CONFIG_SYS_POWER_DEEP_SLEEP protection
in shim drivers as QMSI 1.4 has introduced empty context save/restore
functions that can be called in Quark D2000, therefore keeping common
code at the shim driver level for Quark SE and D2000.

Change-Id: Ia2a466327f999668c6511c0193014e9151bff6ae
Signed-off-by: Juan Solano <juanx.solano.menacho@intel.com>