ARM: smccc: Update HVC comment to describe new quirk parameter

Commit 680a0873 ("arm: kernel: Add SMC structure parameter") added
a new "quirk" parameter to the SMC and HVC SMCCC backends, but only
updated the comment for the SMC version. This patch adds the new
paramater to the comment describing the HVC version too.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

include/linux/arm-smccc.h

@@ -109,6 +109,7 @@ asmlinkage void __arm_smccc_smc(unsigned long a0, unsigned long a1,
  * __arm_smccc_hvc() - make HVC calls
  * @a0-a7: arguments passed in registers 0 to 7
  * @res: result values from registers 0 to 3
+ * @quirk: points to an arm_smccc_quirk, or NULL when no quirks are required.
  *
  * This function is used to make HVC calls following SMC Calling
  * Convention.  The content of the supplied param are copied to registers 0