tree: Make internal functions static

None of these functions are used outside of the files they are defined
in, so make them all static.

Change-Id: Ie9cbe12d289bcedacf2f1bf483ae64ef8039ccc1
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/33667
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/board_enable.c b/board_enable.c
index b5a5442..5876036 100644
--- a/board_enable.c
+++ b/board_enable.c
@@ -67,7 +67,7 @@
 }
 
 /* Winbond W83697 documentation indicates that the index register has to be written for each access. */
-void sio_mask_alzheimer(uint16_t port, uint8_t reg, uint8_t data, uint8_t mask)
+static void sio_mask_alzheimer(uint16_t port, uint8_t reg, uint8_t data, uint8_t mask)
 {
 	uint8_t tmp;
 
@@ -519,7 +519,7 @@
  * Supported chips:
  * W83697HF/F/HG, W83697SF/UF/UG
  */
-void w83697xx_memw_enable(uint16_t port)
+static void w83697xx_memw_enable(uint16_t port)
 {
 	w836xx_ext_enter(port);
 	if (!(sio_read(port, 0x24) & 0x02)) { /* Flash ROM enabled? */