mips: Handle KCOV __init vs inline mismatch

When KCOV is enabled all functions get instrumented, unless
the __no_sanitize_coverage attribute is used. To prepare for
__no_sanitize_coverage being applied to __init functions, we
have to handle differences in how GCC's inline optimizations get
resolved. For mips this requires adding the __init annotation on
init_mips_clocksource().

Reviewed-by: Huacai Chen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Kees Cook <[e-mail]>

arch/mips/include/asm/time.h

···
  */
 extern int init_r4k_clocksource(void);
 
-static inline int init_mips_clocksource(void)
+static inline __init int init_mips_clocksource(void)
 {
 #ifdef CONFIG_CSRC_R4K
 	return init_r4k_clocksource();