docs/library/spi_engine: fix regmap

fix DATA_WIDTH register.

Signed-off-by: Carlos Souza <carlos.souza@analog.com>

Author: caosjr

docs/regmap/adi_regmap_spi_engine.txt

@@ -70,15 +70,15 @@ DATA_WIDTH
 ENDREG
 
 FIELD
-[7:4] NUM_OF_SDI
+[23:16] NUM_OF_SDI
 NUM_OF_SDI
 RO
 Number of SDI.
 It is equal with the maximum supported SDI lines in bits.
 ENDFIELD
 
 FIELD
-[3:0] DATA_WIDTH
+[15:0] DATA_WIDTH
 DATA_WIDTH
 RO
 Data width of the SDI/SDO parallel interface.