kmod-regmap: make regmap-mmio user selectable

REGMAP_MMIO is a hidden symbol, so it cannot be directly selected. If nothing
selects it, it will fail the build with:

ERROR: module '/store/buildbot/slave/slave/rb532/build/build_dir/target-mipsel_mips32_musl-1.1.10/linux-rb532/linux-3.18.19/drivers/base/regmap/regmap-mmio.ko' is missing.
make[2]: *** [/store/buildbot/slave/slave/rb532/build/bin/rb532/packages/base/kmod-regmap_3.18.19-1_rb532.ipk] Error 1

Fix this by adding a description to allow selecting it manually.

Fixes: r46451 ("kmod-regmap: enable MMIO support")
Signed-off-by: Jonas Gorski <jogo@openwrt.org>

SVN-Revision: 46485

target/linux/generic/patches-3.18/259-regmap_dynamic.patch

@@ -30,8 +30,9 @@
  	depends on SPMI
  
  config REGMAP_MMIO
+-	tristate
++	tristate "Regmap MMIO"
 +	select REGMAP
- 	tristate
  
  config REGMAP_IRQ
 +	select REGMAP

target/linux/generic/patches-4.0/259-regmap_dynamic.patch

@@ -34,8 +34,9 @@
  	depends on SPMI
  
  config REGMAP_MMIO
+-	tristate
++	tristate "Regmap MMIO"
 +	select REGMAP
- 	tristate
  
  config REGMAP_IRQ
 +	select REGMAP

target/linux/generic/patches-4.1/259-regmap_dynamic.patch

@@ -34,8 +34,9 @@
  	depends on SPMI
  
  config REGMAP_MMIO
+-	tristate
++	tristate "Regmap MMIO"
 +	select REGMAP
- 	tristate
  
  config REGMAP_IRQ
 +	select REGMAP