Use case range syntax makes the code shorter with better readability when
we have a large number of continuous switch cases.

Below are the summary of readable/volatile/precious registers.

The readable registers:
        0x01 ~  0x0D, 0x0F ~ 0x1C
The volatile registers:
        0x01 ~ 0x05, 0x15 ~ 0x18
The precious registers:
        0x15 ~ 0x18

No functional change with this patch.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Acked-by: NBrian Austin <brian.austin@cirrus.com>
Signed-off-by: NMark Brown <broonie@kernel.org>