ALSA: asihpi - Fix minor typos and spelling

Signed-off-by: Eliot Blennerhassett <eblennerhassett@audioscience.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/asihpi/hpi_internal.h

@@ -602,7 +602,7 @@ struct hpi_data_compat32 {
 #endif
 
 struct hpi_buffer {
-  /** placehoder for backward compatibility (see dwBufferSize) */
+  /** placeholder for backward compatibility (see dwBufferSize) */
 	struct hpi_msg_format reserved;
 	u32 command; /**< HPI_BUFFER_CMD_xxx*/
 	u32 pci_address; /**< PCI physical address of buffer for DSP DMA */