video: driver: amend internal buffer size calculations

Utilize new HFI header to calculate internal buffer sizes.

Change-Id: I0f9e105da4cd346ed377f24b0823152f88150aa4
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>

driver/vidc/inc/hfi_command.h

@@ -6,6 +6,7 @@
 #ifndef __H_HFI_COMMAND_H__
 #define __H_HFI_COMMAND_H__
 
+//todo: DP: remove below headers
 #include <linux/types.h>
 #include <linux/bits.h>