kernel: Remove nvmem hack patch from 5.4

The nvmem framework is now used in net/ethernet/eth.c and the nvmem
sysfs is split into a separate Kconfig option. More work would be needed
to adapt this patch for the broader use. The current patch compiles fine
on ath79, but it breaks the x86 target.

nvmem is also compiled into the kernel for most of our targets for
example ath79 anyway, so patching the kernel to remove it is now harder
and not the case on multiple targets anyway. Instead of making this work
on kernel 5.4 just remove this hack patch.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

package/kernel/linux/modules/other.mk

@@ -139,6 +139,7 @@ $(eval $(call KernelPackage,dma-buf))
 define KernelPackage/nvmem
   SUBMENU:=$(OTHER_MENU)
   TITLE:=Non Volatile Memory support
+  DEPENDS:=@!LINUX_5_4
   KCONFIG:=CONFIG_NVMEM
   HIDDEN:=1
   FILES:=$(LINUX_DIR)/drivers/nvmem/nvmem_core.ko
@@ -169,7 +170,7 @@ define KernelPackage/eeprom-at24
   SUBMENU:=$(OTHER_MENU)
   TITLE:=EEPROM AT24 support
   KCONFIG:=CONFIG_EEPROM_AT24
-  DEPENDS:=+kmod-i2c-core +kmod-nvmem +!LINUX_4_14:kmod-regmap-i2c
+  DEPENDS:=+kmod-i2c-core +!LINUX_5_4:kmod-nvmem +!LINUX_4_14:kmod-regmap-i2c
   FILES:=$(LINUX_DIR)/drivers/misc/eeprom/at24.ko
   AUTOLOAD:=$(call AutoProbe,at24)
 endef
@@ -185,7 +186,7 @@ define KernelPackage/eeprom-at25
   SUBMENU:=$(OTHER_MENU)
   TITLE:=EEPROM AT25 support
   KCONFIG:=CONFIG_EEPROM_AT25
-  DEPENDS:=+kmod-nvmem
+  DEPENDS:=+!LINUX_5_4:kmod-nvmem
   FILES:=$(LINUX_DIR)/drivers/misc/eeprom/at25.ko
   AUTOLOAD:=$(call AutoProbe,at25)
 endef

target/linux/generic/hack-5.4/290-nvmem-make-CONFIG_NVMEM-tristate-again.patch

@@ -1,34 +0,0 @@
-From 2579d9b982c7232f9354bcca5262e26a84c38799 Mon Sep 17 00:00:00 2001
-From: Hauke Mehrtens <hauke@hauke-m.de>
-Date: Fri, 2 Nov 2018 17:40:32 +0100
-Subject: [PATCH] nvmem: make CONFIG_NVMEM tristate again
-
-Only build it in when OF_NET is selected and make it possible to build
-it as module otherwise.
-
-Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
----
- drivers/nvmem/Kconfig | 2 +-
- drivers/of/Kconfig    | 1 +
- 2 files changed, 2 insertions(+), 1 deletion(-)
-
---- a/drivers/nvmem/Kconfig
-+++ b/drivers/nvmem/Kconfig
-@@ -1,6 +1,6 @@
- # SPDX-License-Identifier: GPL-2.0-only
- menuconfig NVMEM
--	bool "NVMEM Support"
-+	tristate "NVMEM Support"
- 	help
- 	  Support for NVMEM(Non Volatile Memory) devices like EEPROM, EFUSES...
- 
---- a/drivers/of/Kconfig
-+++ b/drivers/of/Kconfig
-@@ -72,6 +72,7 @@ config OF_IRQ
- 
- config OF_NET
- 	depends on NETDEVICES
-+	select NVMEM
- 	def_bool y
- 
- config OF_MDIO