ltq-vdsl-vr9-mei: fix ignored-qualifiers build warnings

These functions return the register memory addresses. Usually
they are fixed values, hence I think it's safe to remove the
qualifier "volatile".

Signed-off-by: Shiji Yang <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/18744
Signed-off-by: Robert Marko <[email protected]>
(cherry picked from commit bcf3f96c024872d2ab67b5f0e36f650e0993d1d8)
Signed-off-by: Nora Matthias Schiffer <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20440
Signed-off-by: Hauke Mehrtens <[email protected]>

package/kernel/lantiq/ltq-vdsl-vr9-mei/patches/406-fix-ignored-qualifiers-build-warnings.patch

@@ -0,0 +1,38 @@
+From: Shiji Yang <[email protected]>
+Date: Fri, 9 May 2025 00:58:00 +0800
+Subject: [PATCH] fix ignored-qualifiers build warnings
+
+This patch fixes the following build warnings:
+
+/home/db/owrt/build_dir/target-mips_24kc_musl/linux-lantiq_xrx200/drv_mei_cpe-1.5.17.6/src/drv_mei_cpe_mei_access_vrx.c:41:15: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]
+   41 | static inline volatile IFX_uint32_t MEI_RCU_get(MEI_MEI_DRV_CNTRL_T *pMeiDrvCntrl)
+      |               ^~~~~~~~
+/home/db/owrt/build_dir/target-mips_24kc_musl/linux-lantiq_xrx200/drv_mei_cpe-1.5.17.6/src/drv_mei_cpe_mei_access_vrx.c:56:15: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]
+   56 | static inline volatile IFX_uint32_t MEI_RCU_Slave_get(MEI_MEI_DRV_CNTRL_T *pMeiDrvCntrl)
+      |               ^~~~~~~~
+
+Signed-off-by: Shiji Yang <[email protected]>
+---
+ src/drv_mei_cpe_mei_access_vrx.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/src/drv_mei_cpe_mei_access_vrx.c
++++ b/src/drv_mei_cpe_mei_access_vrx.c
+@@ -38,7 +38,7 @@
+    Local macro definition
+    ========================================================================= */
+ 
+-static inline volatile IFX_uint32_t MEI_RCU_get(MEI_MEI_DRV_CNTRL_T *pMeiDrvCntrl)
++static inline IFX_uint32_t MEI_RCU_get(MEI_MEI_DRV_CNTRL_T *pMeiDrvCntrl)
+ {
+    IFX_uint32_t ret = 0;
+    if (MEI_DEVICE_CFG_IS_PLATFORM(e_MEI_DEV_PLATFORM_CONFIG_VR9))
+@@ -53,7 +53,7 @@ static inline volatile IFX_uint32_t MEI_
+    return ret;
+ }
+ 
+-static inline volatile IFX_uint32_t MEI_RCU_Slave_get(MEI_MEI_DRV_CNTRL_T *pMeiDrvCntrl)
++static inline IFX_uint32_t MEI_RCU_Slave_get(MEI_MEI_DRV_CNTRL_T *pMeiDrvCntrl)
+ {
+    IFX_uint32_t ret = 0;
+    if (MEI_DEVICE_CFG_IS_PLATFORM(e_MEI_DEV_PLATFORM_CONFIG_VR9))