[openwrt/openwrt] include/cmake.mk: add support for overriding the host install prefix

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/a6a9f9be278e718f3f8a5cb7640dd8035cc802b9

commit a6a9f9be278e718f3f8a5cb7640dd8035cc802b9
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Tue Nov 2 18:08:47 2021 +0100

    include/cmake.mk: add support for overriding the host install prefix
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/cmake.mk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/cmake.mk b/include/cmake.mk
index 3318468c90..b9a7e36dee 100644
--- a/include/cmake.mk
+++ b/include/cmake.mk
@@ -52,6 +52,7 @@ CMAKE_RANLIB:=$(call cmake_tool,$(TARGET_RANLIB))
 CMAKE_FIND_ROOT_PATH:=$(STAGING_DIR)/usr;$(TOOLCHAIN_DIR)$(if $(CONFIG_EXTERNAL_TOOLCHAIN),;$(CONFIG_TOOLCHAIN_ROOT))
 CMAKE_HOST_FIND_ROOT_PATH:=$(STAGING_DIR)/host;$(STAGING_DIR_HOSTPKG);$(STAGING_DIR_HOST)
 CMAKE_SHARED_LDFLAGS:=-Wl,-Bsymbolic-functions
+CMAKE_HOST_INSTALL_PREFIX = $(HOST_BUILD_PREFIX)
 
 ifeq ($(HOST_USE_NINJA),1)
   CMAKE_HOST_OPTIONS += -DCMAKE_GENERATOR="Ninja"
@@ -157,7 +158,7 @@ define Host/Configure/Default
 			-DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=ONLY \
 			-DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=ONLY \
 			-DCMAKE_STRIP=: \
-			-DCMAKE_INSTALL_PREFIX=$(HOST_BUILD_PREFIX) \
+			-DCMAKE_INSTALL_PREFIX=$(CMAKE_HOST_INSTALL_PREFIX) \
 			-DCMAKE_PREFIX_PATH=$(HOST_BUILD_PREFIX) \
 			-DCMAKE_SKIP_RPATH=TRUE  \
 			-DCMAKE_INSTALL_LIBDIR=lib \