[MIPS] Sibyte: Fix ZBbus profiler

 o Fix build error.
 o Handle error returns.
 o Deal with signals received while sleeping.
 o Don't allow to be selected when we're not building the directory with
   the driver anyway.
 o Coding style cleanups.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/sibyte/Kconfig

@@ -8,24 +8,28 @@ config SIBYTE_SB1250
 config SIBYTE_BCM1120
 	bool
 	select SIBYTE_BCM112X
+	select SIBYTE_HAS_ZBUS_PROFILING
 	select SIBYTE_SB1xxx_SOC
 
 config SIBYTE_BCM1125
 	bool
 	select HW_HAS_PCI
 	select SIBYTE_BCM112X
+	select SIBYTE_HAS_ZBUS_PROFILING
 	select SIBYTE_SB1xxx_SOC
 
 config SIBYTE_BCM1125H
 	bool
 	select HW_HAS_PCI
 	select SIBYTE_BCM112X
 	select SIBYTE_ENABLE_LDT_IF_PCI
+	select SIBYTE_HAS_ZBUS_PROFILING
 	select SIBYTE_SB1xxx_SOC
 
 config SIBYTE_BCM112X
 	bool
 	select SIBYTE_SB1xxx_SOC
+	select SIBYTE_HAS_ZBUS_PROFILING
 
 config SIBYTE_BCM1x80
 	bool
@@ -37,6 +41,7 @@ config SIBYTE_BCM1x55
 	bool
 	select HW_HAS_PCI
 	select SIBYTE_SB1xxx_SOC
+	select SIBYTE_HAS_ZBUS_PROFILING
 	select SYS_SUPPORTS_SMP
 
 config SIBYTE_SB1xxx_SOC
@@ -164,5 +169,8 @@ config SIBYTE_SB1250_PROF
 	depends on SIBYTE_SB1xxx_SOC
 
 config SIBYTE_TBPROF
-	bool "Support for ZBbus profiling"
-	depends on SIBYTE_SB1xxx_SOC
+	tristate "Support for ZBbus profiling"
+	depends on SIBYTE_HAS_ZBUS_PROFILING
+
+config SIBYTE_HAS_ZBUS_PROFILING
+	bool