[arm] Use correct DHCP client architecture values

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/arm32/include/efi/ipxe/dhcp_arch.h

 		      'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0' )
 
 #define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_EFI )
+	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_ARM32 )
 
 #define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 3, 10 /* v3.10 */ )
 

src/arch/arm64/include/efi/ipxe/dhcp_arch.h

 		      'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0' )
 
 #define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_EFI )
+	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_ARM64 )
 
 #define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 3, 10 /* v3.10 */ )
 

src/include/ipxe/dhcp.h

 	DHCP_CLIENT_ARCHITECTURE_XSCALE = 0x0008,
 	/** EFI x86-64 */
 	DHCP_CLIENT_ARCHITECTURE_X86_64 = 0x0009,
+	/** EFI 32-bit ARM */
+	DHCP_CLIENT_ARCHITECTURE_ARM32 = 0x000a,
+	/** EFI 64-bit ARM */
+	DHCP_CLIENT_ARCHITECTURE_ARM64 = 0x000b,
 };
 
 /** Client network device interface */