Add 'const' keyword to chip write and other function prototypes

Corresponding to flashrom svn r1789.

Inspired by and mostly based on a patch
Signed-off-by: Mark Marshall <mark.marshall@omicron.at>

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/layout.c b/layout.c
index 0e49f19..a12eb28 100644
--- a/layout.c
+++ b/layout.c
@@ -45,7 +45,7 @@
 static int num_include_args = 0; /* the number of valid include_args. */
 
 #ifndef __LIBPAYLOAD__
-int read_romlayout(char *name)
+int read_romlayout(const char *name)
 {
 	FILE *romlayout;
 	char tempstr[256];
@@ -102,7 +102,7 @@
 #endif
 
 /* returns the index of the entry (or a negative value if it is not found) */
-int find_include_arg(const char *const name)
+static int find_include_arg(const char *const name)
 {
 	unsigned int i;
 	for (i = 0; i < num_include_args; i++) {