kconfig: Clean up header comments and make them consistent

Use this short header style in all Kconfig files:

    # <description>

    # <copyright>
    # <license>

    ...

Also change all <description>s from

    # Kconfig[.extension] - Foo-related options

to just

    # Foo-related options

It's clear enough that it's about Kconfig.

The <description> cleanup was done with this command, along with some
manual cleanup (big letter at the start, etc.)

    git ls-files '*Kconfig*' | \
        xargs sed -i -E '1 s/#\s*Kconfig[\w.-]*\s*-\s*/# /'

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>

drivers/i2s/Kconfig

@@ -1,8 +1,7 @@
-# Kconfig - I2S (Inter-IC Sound) driver configuration options
-#
+# I2S (Inter-IC Sound) driver configuration options
+
 # Copyright (c) 2017 Piotr Mienkowski
 # SPDX-License-Identifier: Apache-2.0
-#
 
 #
 # I2S Drivers

drivers/i2s/Kconfig.cavs

@@ -1,9 +1,7 @@
-# Kconfig - Intel S1000 I2S configuration options
-#
+# Intel S1000 I2S configuration options
+
 # Copyright (c) 2017 Intel Corporation
-#
 # SPDX-License-Identifier: Apache-2.0
-#
 
 menuconfig I2S_CAVS
 	bool "Intel I2S (SSP) Bus Driver"

drivers/i2s/Kconfig.sam_ssc

@@ -1,9 +1,7 @@
-# Kconfig - Atmel SAM I2S bus driver configuration options
-#
+# Atmel SAM I2S bus driver configuration options
+
 # Copyright (c) 2017 Piotr Mienkowski
-#
 # SPDX-License-Identifier: Apache-2.0
-#
 
 menuconfig I2S_SAM_SSC
 	bool "Atmel SAM MCU family I2S (SSC) Bus Driver"

drivers/i2s/Kconfig.stm32

@@ -1,9 +1,7 @@
-# Kconfig - STM32 I2S driver configuration options
-#
+# STM32 I2S driver configuration options
+
 # Copyright (c) 2018 STMicroelectronics
-#
 # SPDX-License-Identifier: Apache-2.0
-#
 
 menuconfig I2S_STM32
 	bool "STM32 MCU I2S controller driver"