regulator: dt-bindings: rpmh-regulator: Update pmic-id DT prop info for new CMD-DB

Currently, CMD-DB names for RPMH regulators follow this format:
`^(smps|ldo|bob|vs)[a-n][1-9][0-9]?$`

Here, the `[a-n]` value is read from the `pmic-id` DT property,
which is unique to each PMIC present on the board.

Note that in this older CMD-DB name format the SPMI bus on which
a particular PMIC regulator exists was not apparent from its
CMD-DB name.

New targets like Glymur, where we have multiple SPMI buses,
overcome this limitation by following a new CMD-DB name format:
`^(L|S|B)[1-9][0-9]?[A-N]_E[0-3]$`

Here `[A-N]_E[0-3]` part will now be read from the `pmic-id` DT
prop and it includes the SPMI bus id `[0-3]` as well.

However, the PMIC ID part `[A-N]` of the CMD-DB name is now
unique only to the SPMI bus that the PMIC regulator is present
on.  which means `L1B_E0` and `L1B_E1` are both possible CMD-DB
names for two different regulator LDOs present on two different
SPMI buses (bus id 0 and 1) on the same board.

Note that since the new `pmic-id` DT property is a combo of
PMIC ID and SPMI bus ID, so its still unique to each PMIC
present on the board.

Update the `pmic-id` property pattern information to reflect this
change in the driver handling to support this new CMD-DB naming
format while maintaining backward compatiblilty with old CMD-DB
naming format which is still supported for older/existing
targets.

Signed-off-by: Kamal Wadhwa <kamal.wadhwa@oss.qualcomm.com>
Link: https://patch.msgid.link/20250918-glymur-rpmh-regulator-driver-v3-2-184c09678be3@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/qcom,rpmh-regulator.yaml

@@ -108,7 +108,7 @@ properties:
         RPMh resource name suffix used for the regulators found
         on this PMIC.
     $ref: /schemas/types.yaml#/definitions/string
-    enum: [a, b, c, d, e, f, g, h, i, j, k, l, m, n]
+    pattern: "^[a-n]|[A-N]_E[0-3]+$"
 
   qcom,always-wait-for-ack:
     description: |