[EFR32 OTA] Update the efr32_sdk submodule pointer (#14467)

* Update the efr32_sdk submodule pointer and README file

* Restyled by prettier-markdown

* Update the dictionary

* Don't include chip-shell by default

Co-authored-by: Restyled.io <[email protected]>

.github/.wordlist.txt

@@ -938,6 +938,7 @@ SoftwareVersion
 SoftwareVersionString
 softwareVersionValid
 SPI
+spiflash
 spinel
 src
 SRP

examples/ota-requestor-app/efr32/README.md

@@ -80,8 +80,13 @@ See `examples/lighting-app/efr32/README.md`
 
 -   Build or download the Gecko Bootloader binary. Bootloader should be built
     with the Gecko SDK version 3.2.1 or earlier, type "external SPI" configured
-    with a single slot of at least 1000 KB. Using the commander tool upload the
-    bootloader to the device running the requestor application.
+    with a single slot of at least 1000 KB. Pre-built binaries should be
+    available in
+
+           third_party/efr32_sdk/repo/platform/bootloader/sample-apps/bootloader-storage-spiflash-single
+
+-   Using the commander tool upload the bootloader to the device running the
+    requestor application.
 
 -   Create a bootable image file:
 

examples/ota-requestor-app/efr32/args.gni

@@ -25,5 +25,4 @@ chip_openthread_ftd = false
 
 declare_args() {
   chip_enable_ota_requestor = true
-  chip_build_libshell = true
 }