arm: Add .arch directives for armv6

This allows building these files as part of a fat build, even if
the assembler by default targets a lower architecture version.

arm/v6/aes-decrypt-internal.asm

@@ -30,6 +30,8 @@ ifelse(<
    not, see http://www.gnu.org/licenses/.
 >) 
 
+	.arch armv6
+
 include_src(<arm/aes.m4>)
 
 define(<PARAM_ROUNDS>, <r0>)

arm/v6/aes-encrypt-internal.asm

@@ -30,6 +30,8 @@ ifelse(<
    not, see http://www.gnu.org/licenses/.
 >) 
 
+	.arch armv6
+
 include_src(<arm/aes.m4>)
 
 C	Benchmarked at at 706, 870, 963 cycles/block on cortex A9,

arm/v6/sha1-compress.asm

@@ -31,6 +31,7 @@ ifelse(<
 >) 
 
 	.file "sha1-compress.asm"
+	.arch armv6
 
 define(<STATE>, <r0>)
 define(<INPUT>, <r1>)

arm/v6/sha256-compress.asm

@@ -31,6 +31,7 @@ ifelse(<
 >) 
 
 	.file "sha256-compress.asm"
+	.arch armv6
 
 define(<STATE>, <r0>)
 define(<INPUT>, <r1>)