firmware: qcom_scm: update comment for ICE-related functions

The SCM calls QCOM_SCM_ES_INVALIDATE_ICE_KEY and
QCOM_SCM_ES_CONFIG_SET_ICE_KEY are also needed for eMMC inline
encryption support, not just for UFS. Update the comments accordingly.

Reviewed-by: Satya Tangirala <[e-mail]>
Acked-by: Bjorn Andersson <[e-mail]>
Signed-off-by: Eric Biggers <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/firmware/qcom_scm.c

···
  * qcom_scm_ice_invalidate_key() - Invalidate an inline encryption key
  * @index: the keyslot to invalidate
  *
- * The UFSHCI standard defines a standard way to do this, but it doesn't work on
- * these SoCs; only this SCM call does.
+ * The UFSHCI and eMMC standards define a standard way to do this, but it
+ * doesn't work on these SoCs; only this SCM call does.
+ *
+ * It is assumed that the SoC has only one ICE instance being used, as this SCM
+ * call doesn't specify which ICE instance the keyslot belongs to.
  *
  * Return: 0 on success; -errno on failure.
  */
···
  *		    units, e.g. 1 = 512 bytes, 8 = 4096 bytes, etc.
  *
  * Program a key into a keyslot of Qualcomm ICE (Inline Crypto Engine), where it
- * can then be used to encrypt/decrypt UFS I/O requests inline.
+ * can then be used to encrypt/decrypt UFS or eMMC I/O requests inline.
  *
- * The UFSHCI standard defines a standard way to do this, but it doesn't work on
- * these SoCs; only this SCM call does.
+ * The UFSHCI and eMMC standards define a standard way to do this, but it
+ * doesn't work on these SoCs; only this SCM call does.
+ *
+ * It is assumed that the SoC has only one ICE instance being used, as this SCM
+ * call doesn't specify which ICE instance the keyslot belongs to.
  *
  * Return: 0 on success; -errno on failure.
  */