spi: lm70llp: fix links in doc and comments

Update links in the documentation and in-code comments which point to
the datasheet and schematic.

The current links don't work because National Semiconductor (which is
the manufacturer of this board and lm70) has been a part of Texas
Instruments since 2011 and hence http://www.national.com/ doesn't work
anymore.

Fixes: 78961a574037 ("spi_lm70llp parport adapter driver")
Fixes: 2b7300513b98 ("hwmon: (lm70) Code streamlining and cleanup")
Signed-off-by: Kousik Sanagavarapu <[e-mail]>
Link: https://msgid.link/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

Documentation/spi/spi-lm70llp.rst

···
 
   * National Semiconductor LM70 LLP evaluation board
 
-    Datasheet: http://www.national.com/pf/LM/LM70.html
+    Datasheet: https://www.ti.com/lit/gpn/lm70
 
 Author:
         Kaiwan N Billimoria <[e-mail]>
···
 The schematic for this particular board (the LM70EVAL-LLP) is
 available (on page 4) here:
 
-  http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf
+  https://download.datasheets.com/pdfs/documentation/nat/kit&board/lm70llpevalmanual.pdf
 
 The hardware interfacing on the LM70 LLP eval board is as follows:
 

drivers/spi/spi-lm70llp.c

···
  *
  * Datasheet and Schematic:
  * The LM70 is a temperature sensor chip from National Semiconductor; its
- * datasheet is available at http://www.national.com/pf/LM/LM70.html
+ * datasheet is available at https://www.ti.com/lit/gpn/lm70
  * The schematic for this particular board (the LM70EVAL-LLP) is
  * available (on page 4) here:
- *  http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf
+ *  https://download.datasheets.com/pdfs/documentation/nat/kit&board/lm70llpevalmanual.pdf
  *
  * Also see Documentation/spi/spi-lm70llp.rst.  The SPI<->parport code here is
  * (heavily) based on spi-butterfly by David Brownell.