tree: Make internal variables static

All these variables are only used in the files they are defined in, so
they can be made static.

Change-Id: I1e55138adef540e9d3a2237aa5b289cb338c0608
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/33747
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/it85spi.c b/it85spi.c
index 1d1ecad..3dbba78 100644
--- a/it85spi.c
+++ b/it85spi.c
@@ -74,9 +74,9 @@
 #endif  /* LPC_IO */
 
 #ifdef LPC_IO
-unsigned int shm_io_base;
+static unsigned int shm_io_base;
 #endif
-unsigned char *ce_high, *ce_low;
+static unsigned char *ce_high, *ce_low;
 static int it85xx_scratch_rom_reenter = 0;
 
 /* This function will poll the keyboard status register until either