Rename getenv_r() into getenv_f()

While running from flash, i. e. before relocation, we have only a
limited C runtime environment without writable data segment. In this
phase, some configurations (for example with environment in EEPROM)
must not use the normal getenv(), but a special function.  This
function had been called getenv_r(), with the idea that the "_r"
suffix would mean the same as in the _r_eentrant versions of some of
the C library functions (for example getdate vs. getdate_r, getgrent
vs. getgrent_r, etc.).

Unfortunately this was a misleading name, as in U-Boot the "_r"
generally means "running from RAM", i. e. _after_ relocation.

To avoid confusion, rename into getenv_f() [as "running from flash"]

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
diff --git a/arch/mips/cpu/incaip_clock.c b/arch/mips/cpu/incaip_clock.c
index fc2c621..b65dfe0 100644
--- a/arch/mips/cpu/incaip_clock.c
+++ b/arch/mips/cpu/incaip_clock.c
@@ -105,7 +105,7 @@
 	char tmp[64];
 	ulong cpuclk;
 
-	if (getenv_r ("cpuclk", tmp, sizeof (tmp)) > 0) {
+	if (getenv_f("cpuclk", tmp, sizeof (tmp)) > 0) {
 		cpuclk = simple_strtoul (tmp, NULL, 10) * 1000000;
 		cgu_init (cpuclk);
 		ebu_init (cpuclk);
diff --git a/arch/mips/lib/board.c b/arch/mips/lib/board.c
index b2d113e..ab4a17c 100644
--- a/arch/mips/lib/board.c
+++ b/arch/mips/lib/board.c
@@ -114,7 +114,7 @@
 static int init_baudrate (void)
 {
 	char tmp[64];	/* long enough for environment variables */
-	int i = getenv_r ("baudrate", tmp, sizeof (tmp));
+	int i = getenv_f("baudrate", tmp, sizeof (tmp));
 
 	gd->baudrate = (i > 0)
 			? (int) simple_strtoul (tmp, NULL, 10)