CONFIG_SYS_CLK_FREQ: Consistently be static or get_board_sys_clk()

This CONFIG option is used in one of two ways.  The first way is that it
is defined to a static value, of an unsigned long size.  The second way
is that it is defined to something, typically a function, to determine
this value at run time.

However, in a few cases that function returns a static value.  Change
that to using the static value directly.

In the case of using something at run time, convert everything to using
a function of the same name and prototype.  This will allow for further
cleanups.

Finally, we have a few cases where the function is just not used, so
drop it.

Signed-off-by: Tom Rini <trini@konsulko.com>

board/cadence/xtfpga/xtfpga.c

@@ -49,7 +49,7 @@ int checkboard(void)
 	return 0;
 }
 
-int board_postclk_init(void)
+unsigned long get_board_sys_clk(void)
 {
 	/*
 	 * Obtain CPU clock frequency from board and cache in global
@@ -58,11 +58,17 @@ int board_postclk_init(void)
 	 */
 
 #ifdef CONFIG_SYS_FPGAREG_FREQ
-	gd->cpu_clk = (*(volatile unsigned long *)CONFIG_SYS_FPGAREG_FREQ);
+	return (*(volatile unsigned long *)CONFIG_SYS_FPGAREG_FREQ);
 #else
 	/* early Tensilica bitstreams lack this reg, but most run at 50 MHz */
-	gd->cpu_clk = 50000000UL;
+	return 50000000;
 #endif
+}
+
+int board_postclk_init(void)
+{
+	gd->cpu_clk = get_board_sys_clk();
+
 	return 0;
 }