exynos5250/snow: deprecate time.h

This re-introduces 2fde966 (http://review.coreboot.org/#/c/3177/)
which was reverted due to unsatisfied dependencies.

time.h We Hardly Knew Ye.

This deprecates time.h which is currently only used by Exynos5250 and
Snow. The original idea was to try and unify some of the various timer
interfaces and has been supplanted by the monotonic timer API.

timer_us() is now obsolete. timer_start() is now mct_start() and
is exposed in exynos5250/clk.h.

Change-Id: I8e60105629d9da68ed622e89209b3ef6c8e2445b
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/3201
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/cpu/samsung/exynos5250/clk.h

@@ -585,6 +585,7 @@ int clock_get_mem_selection(enum ddr_mode *mem_type,
 		unsigned *frequency_mhz, unsigned *arm_freq,
 		enum mem_manuf *mem_manuf);
 
+void mct_start(void);
 uint64_t mct_raw_value(void);
 
 #endif

src/cpu/samsung/exynos5250/mct.c

@@ -22,7 +22,7 @@
 
 #include <arch/io.h>
 #include <stdint.h>
-#include <time.h>
+
 #include "clk.h"
 
 struct __attribute__((packed)) mct_regs
@@ -101,16 +101,8 @@ uint64_t mct_raw_value(void)
 	return (upper << 32) | lower;
 }
 
-void timer_start(void)
+void mct_start(void)
 {
 	writel(readl(&mct->g_tcon) | (0x1 << 8), &mct->g_tcon);
 	enabled = 1;
 }
-
-u32 timer_us(void)
-{
-	uint64_t raw = mct_raw_value();
-	static uint32_t ticks_per_microsecond = MCT_HZ/1000000;
-	uint32_t usec = raw / ticks_per_microsecond;
-	return usec;
-}

src/cpu/samsung/exynos5250/monotonic_timer.c

@@ -20,7 +20,6 @@
 #include <stdint.h>
 #include <delay.h>
 #include <timer.h>
-#include <time.h>	/* TODO: deprecate in favor of monotonic timer stuff */
 
 #include "clk.h"