iwlwifi: remove incorrect comment in pnvm

We use this driver as a backport that also runs on older kernels (as
part of the backports project).  So we use some checks to backport or
prevent code from compiling in incompatible kernel version.

When I took one of the PNVM patches from the backport, I accidentally
left the comment that a certain part of the code doesn't work in older
kernels.  This obviously should never be valid for the mainline.
Remove this comment.
Reported-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210211223049.40d545a0fa89.I04793aaa5312b926335c8db32131f000432df511@changeid

drivers/net/wireless/intel/iwlwifi/fw/pnvm.c

@@ -220,11 +220,6 @@ static int iwl_pnvm_parse(struct iwl_trans *trans, const u8 *data,
 	return -ENOENT;
 }
 
-/*
- * This is known to be broken on v4.19 and to work on v5.4.  Until we
- * figure out why this is the case and how to make it work, simply
- * disable the feature in old kernels.
- */
 #if defined(CONFIG_EFI)
 
 #define IWL_EFI_VAR_GUID EFI_GUID(0x92daaf2f, 0xc02b, 0x455b,	\