arch/Config.in.x86: fix bonnell typo

Commit [1] added several x86 cpu variant and introduced a typo
(bonnel) on bonnell cpu.

Rename BR2_x86_bonnel to BR2_x86_bonnell without legacy
handling since it never worked.

Fixes:
http://autobuild.buildroot.net/results/2418106d30e07cf09834941e610c75dde78816d2/

[1] 653fa001f30414165cb54dde577688d78cca6b42

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

arch/Config.in.x86

@@ -286,9 +286,9 @@ config BR2_x86_atom
 	select BR2_X86_CPU_HAS_SSSE3
 	help
 	  This option is deprecated. Since gcc 4.9, the gcc option
-	  "bonnel" is preferred. Use BR2_x86_bonnel instead.
-config BR2_x86_bonnel
-	bool "bonnel"
+	  "bonnell" is preferred. Use BR2_x86_bonnell instead.
+config BR2_x86_bonnell
+	bool "bonnell"
 	select BR2_X86_CPU_HAS_MMX
 	select BR2_X86_CPU_HAS_SSE
 	select BR2_X86_CPU_HAS_SSE2
@@ -598,7 +598,7 @@ config BR2_GCC_TARGET_ARCH
 	default "broadwell"	if BR2_x86_broadwell
 	default "skylake"	if BR2_x86_skylake
 	default "atom"		if BR2_x86_atom
-	default "bonnel"	if BR2_x86_bonnel
+	default "bonnell"	if BR2_x86_bonnell
 	default "westmere"	if BR2_x86_westmere
 	default "silvermont"	if BR2_x86_silvermont
 	default "goldmont"	if BR2_x86_goldmont