ASoC: msm8x16-wcd: Make LINEOUT register entries as readable

After ADSP SSR, LINEOUT register entries aren't updated correctly,
causing volume drop on speaker. These entries weren't added as
readable, hence not being cached when the ADSP goes offline.
During SSR, register values should be cached and once the device
is up do a cache sync, to maintain proper register configuration.

CRs-Fixed: 991426
Change-Id: I0257b9c9ae5a24a05e03c1b783b992113235dff2
Signed-off-by: Venkata Narendra Kumar Gutta <vgutta@codeaurora.org>