thermal: Rephrase the Kconfig text for thermal

The thermal subsystem may have relied on sysfs in 2008 when it
was introduced, but these days the thermal zones will more often
than not come from the hardware descriptions and not from sysfs.

Drop the "Generic" phrases as well: there are no non-generic
drivers that I know of, the thermal framework is by definition
generic.

Reword a bit and fix some grammar.

[ Daniel Lezcano ] : fixed Randy's comment s/offers/offer/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200229204527.143796-1-linus.walleij@linaro.org

drivers/thermal/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 #
-# Generic thermal sysfs drivers configuration
+# Generic thermal drivers configuration
 #
 
 menuconfig THERMAL
-	bool "Generic Thermal sysfs driver"
+	bool "Thermal drivers"
 	help
-	  Generic Thermal Sysfs driver offers a generic mechanism for
+	  Thermal drivers offer a generic mechanism for
 	  thermal management. Usually it's made up of one or more thermal
-	  zone and cooling device.
+	  zones and cooling devices.
 	  Each thermal zone contains its own temperature, trip points,
-	  cooling devices.
-	  All platforms with ACPI thermal support can use this driver.
+	  and cooling devices.
+	  All platforms with ACPI or Open Firmware thermal support can use
+	  this driver.
 	  If you want this support, you should say Y here.
 
 if THERMAL