staging: most: dim2: hal: Fix one kernel-doc header and demote two non-conforming ones

Fixes the following W=1 kernel build warning(s):

drivers/staging/most/dim2/hal.c:99: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
drivers/staging/most/dim2/hal.c:788: warning: Function parameter or member 'buf_size' not described in 'dim_norm_isoc_buffer_size'
drivers/staging/most/dim2/hal.c:788: warning: Function parameter or member 'packet_length' not described in 'dim_norm_isoc_buffer_size'
drivers/staging/most/dim2/hal.c:788: warning: expecting prototype for Retrieves maximal possible correct buffer size for isochronous data type(). Prototype was for dim_norm_isoc_buffer_size() instead
drivers/staging/most/dim2/hal.c:802: warning: Function parameter or member 'buf_size' not described in 'dim_norm_sync_buffer_size'
drivers/staging/most/dim2/hal.c:802: warning: Function parameter or member 'bytes_per_frame' not described in 'dim_norm_sync_buffer_size'
drivers/staging/most/dim2/hal.c:802: warning: expecting prototype for Retrieves maximal possible correct buffer size for synchronous data type(). Prototype was for dim_norm_sync_buffer_size() instead

Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Andrey Shvetsov <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/most/dim2/hal.c

···
 
 /**
  * Allocates DBR memory.
- * @param size Allocating memory size.
+ * @size: Allocating memory size.
  * @return Offset in DBR memory by success or DBR_SIZE if out of memory.
  */
 static int alloc_dbr(u16 size)
···
 	writel(0, &g.dim2->MS1);
 }
 
-/**
+/*
  * Retrieves maximal possible correct buffer size for isochronous data type
  * conform to given packet length and not bigger than given buffer size.
  *
···
 	return norm_isoc_buffer_size(buf_size, packet_length);
 }
 
-/**
+/*
  * Retrieves maximal possible correct buffer size for synchronous data type
  * conform to given bytes per frame and not bigger than given buffer size.
  *