staging: sm750fb: sm750_accel: Provide description for 'accel' and fix function naming

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

 drivers/staging/sm750fb/sm750_accel.c:155: warning: Function parameter or member 'accel' not described in 'sm750_hw_copyarea'
 drivers/staging/sm750fb/sm750_accel.c:155: warning: expecting prototype for sm750_hm_copyarea(). Prototype was for sm750_hw_copyarea() instead
 drivers/staging/sm750fb/sm750_accel.c:321: warning: Function parameter or member 'accel' not described in 'sm750_hw_imageblit'

Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Teddy Wang <teddy.wang@siliconmotion.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-staging@lists.linux.dev
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210414181129.1628598-26-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/sm750_accel.c

@@ -131,7 +131,8 @@ int sm750_hw_fillrect(struct lynx_accel *accel,
 }
 
 /**
- * sm750_hm_copyarea
+ * sm750_hw_copyarea
+ * @accel: Acceleration device data
  * @sBase: Address of source: offset in frame buffer
  * @sPitch: Pitch value of source surface in BYTE
  * @sx: Starting x coordinate of source surface
@@ -298,6 +299,7 @@ static unsigned int deGetTransparency(struct lynx_accel *accel)
 
 /**
  * sm750_hw_imageblit
+ * @accel: Acceleration device data
  * @pSrcbuf: pointer to start of source buffer in system memory
  * @srcDelta: Pitch value (in bytes) of the source buffer, +ive means top down
  *	      and -ive mean button up