ACPI: remove redundant 'default n' from Kconfig

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f467c564 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:

    ...
    One side effect of (and the main motivation for) this change is making
    the following two definitions behave exactly the same:

        config FOO
                bool

        config FOO
                bool
                default n

    With this change, neither of these will generate a
    '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
    That might make it clearer to people that a bare 'default n' is
    redundant.
    ...
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/Kconfig

@@ -138,7 +138,6 @@ config ACPI_REV_OVERRIDE_POSSIBLE
 
 config ACPI_EC_DEBUGFS
 	tristate "EC read/write access through /sys/kernel/debug/ec"
-	default n
 	help
 	  Say N to disable Embedded Controller /sys/kernel/debug interface
 
@@ -283,7 +282,6 @@ config ACPI_PROCESSOR
 config ACPI_IPMI
 	tristate "IPMI"
 	depends on IPMI_HANDLER
-	default n
 	help
 	  This driver enables the ACPI to access the BMC controller. And it
 	  uses the IPMI request/response message to communicate with BMC
@@ -361,7 +359,6 @@ config ACPI_TABLE_UPGRADE
 
 config ACPI_DEBUG
 	bool "Debug Statements"
-	default n
 	help
 	  The ACPI subsystem can produce debug output.  Saying Y enables this
 	  output and increases the kernel size by around 50K.
@@ -374,7 +371,6 @@ config ACPI_DEBUG
 config ACPI_PCI_SLOT
 	bool "PCI slot detection driver"
 	depends on SYSFS
-	default n
 	help
 	  This driver creates entries in /sys/bus/pci/slots/ for all PCI
 	  slots in the system.  This can help correlate PCI bus addresses,
@@ -436,7 +432,6 @@ config ACPI_HED
 config ACPI_CUSTOM_METHOD
 	tristate "Allow ACPI methods to be inserted/replaced at run time"
 	depends on DEBUG_FS
-	default n
 	help
 	  This debug facility allows ACPI AML methods to be inserted and/or
 	  replaced without rebooting the system. For details refer to:
@@ -481,7 +476,6 @@ config ACPI_EXTLOG
 	tristate "Extended Error Log support"
 	depends on X86_MCE && X86_LOCAL_APIC && EDAC
 	select UEFI_CPER
-	default n
 	help
 	  Certain usages such as Predictive Failure Analysis (PFA) require
 	  more information about the error than what can be described in