Switched to v2.6-branch. It included x86 EFI binary fix.

It requried rebasing of yocto toolchain patch.

Commits included:
837ab4a915 ARC: save/restore accumulator registers on all ARCv2 HS CPUs by default
0943608550 riscv: openisa_rv32m1: Fix booting of rv32m1_vega
3c56e0df0b cmake: ld: Disable manual linking of libgcc components for host
b0cb7412b9 cmake: host-gcc: Remove libgcc library path resolution
80e1b785dc cmake: host-gcc: Detect libgcc for all archs
e72a327107 cmake: gcc: Remove no_libgcc exclusion for libgcc detection
1cf1d75d3f Bluetooth: Controller: Fix Data Length Update node Rx reservations
e43afd10f7 Bluetooth: Controller: Fix free rx buffer MFIFO enqueue
6d9b318dca Bluetooth: Controller: Minor change to use IS_ENABLED
d4d362d081 doc: api: fix devicetree modification version
d0dca15734 arch/x86/zefi: Fix entry-nop hack for EFI entry
218e438f3e drivers: bluetooth: hci driver for stm32wb includes clock control
f66d0cea06 Tracing: TraceRecorder CMake update
d5a1a22b1a python-devicetree: tox: fix mypy
c77f8fae83 doc/guides/dts: bindings: Fix code snippet for 'signal-gpios'
3ec1caa504 dts/arm: st: g0: closes parenthesis for soc
a221f358eb drivers: flash_stm32_v1: fix a potential unaligned access
f5a6110b4a tests: cpp: libcxx: Test with full and nano variants of newlib
1d6106fd5e tests: cpp: libcxx: Use full version of newlib for testing
4b87e90167 cpp: Fix C++ exception handling newlib dependency
1d4d16b748 linker: cpp: Fix C++ exception handling info section linking
4a564cdef0 version: add EXTRAVERSION to VERSION file

Signed-off-by: Naveen Saini <naveen.kumar.saini@intel.com>