ALSA: emu10k1: pull in some register definitions from kX-project

For documentation purposes and later use.

Some pre-existing but (mostly) unused definitions were renamed for
consistency.
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230422161021.1143903-6-oswald.buddenhagen@gmx.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/emu10k1/emu10k1_main.c

@@ -1953,7 +1953,7 @@ static const unsigned char saved_regs[] = {
 	0xff /* end */
 };
 static const unsigned char saved_regs_audigy[] = {
-	A_ADCIDX, A_MICIDX, A_FXWC1, A_FXWC2, A_SAMPLE_RATE,
+	A_ADCIDX, A_MICIDX, A_FXWC1, A_FXWC2, A_EHC,
 	A_FXRT2, A_SENDAMOUNTS, A_FXRT1,
 	0xff /* end */
 };