ide: preparations for /proc/ide/hd*/settings rework

After rework settings will be no longer created dynamically
for each device so we need to make some fixups first.

* Use set_[ksettings,unmaskirq]() as a set function for
  ["keepsettings","unmaskirq"] setting.

* Allow writes to ["io_32bit","unmaskirq"] settings also when
  drive->no_[io_32bit,unmask] is set (this is checked later inside
  set_[io_32bit,unmaskirq]() anywyay and keeps consistency with
  the corresponding HDIO_SET_[32BIT,UNMASKINTR] ioctls).

* Use max possible multi sectors value (16) as an allowed max for
  "multcount" setting.  set_multcount() set function checks against
  device's max possbile value anyway and it makes the proc setting
  consistent with the corresponding HDIO_SET_MULTCOUNT ioctl.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-proc.c b/drivers/ide/ide-proc.c
index cbe5a7e..7a64aed 100644
--- a/drivers/ide/ide-proc.c
+++ b/drivers/ide/ide-proc.c
@@ -368,11 +368,11 @@
 /*
  *			  drive		setting name		read/write access				data type	min	max				mul_factor	div_factor	data pointer			set function
  */
-	__ide_add_setting(drive,	"io_32bit",		drive->no_io_32bit ? SETTING_READ : SETTING_RW,	TYPE_BYTE,	0,	1 + (SUPPORT_VLB_SYNC << 1),	1,		1,		&drive->io_32bit,		set_io_32bit,	0);
-	__ide_add_setting(drive,	"keepsettings",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->keep_settings,		NULL,		0);
+	__ide_add_setting(drive,	"io_32bit",		SETTING_RW,					TYPE_BYTE,	0,	1 + (SUPPORT_VLB_SYNC << 1),	1,		1,		&drive->io_32bit,		set_io_32bit,	0);
+	__ide_add_setting(drive,	"keepsettings",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->keep_settings,		set_ksettings,	0);
 	__ide_add_setting(drive,	"nice1",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->nice1,			NULL,		0);
 	__ide_add_setting(drive,	"pio_mode",		SETTING_WRITE,					TYPE_BYTE,	0,	255,				1,		1,		NULL,				set_pio_mode,	0);
-	__ide_add_setting(drive,	"unmaskirq",		drive->no_unmask ? SETTING_READ : SETTING_RW,	TYPE_BYTE,	0,	1,				1,		1,		&drive->unmask,			NULL,		0);
+	__ide_add_setting(drive,	"unmaskirq",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->unmask,			set_unmaskirq,	0);
 	__ide_add_setting(drive,	"using_dma",		SETTING_RW,					TYPE_BYTE,	0,	1,				1,		1,		&drive->using_dma,		set_using_dma,	0);
 	__ide_add_setting(drive,	"init_speed",		SETTING_RW,					TYPE_BYTE,	0,	70,				1,		1,		&drive->init_speed,		NULL,		0);
 	__ide_add_setting(drive,	"current_speed",	SETTING_RW,					TYPE_BYTE,	0,	70,				1,		1,		&drive->current_speed,		set_xfer_rate,	0);